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40-channel, 3 v/5 v, single-supply, 14-bit, dense dac data sheet ad5380 rev. d document feedback information furnished by analog devices is believed to be accurate and reliable. however, no responsibility is assumed by analog devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. specifications subject to change without notice. no license is granted by implication or otherwise under any patent or patent rights of analog devices. trademarks and registered trademarks are the property of their respective owners. one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 781.329.4700 ?2004C2014 analog devices, inc. all rights reserved. technical support www.analog.com features guaranteed monotonic inl error: 4 lsb max on-chip 1.25 v/2.5 v, 10 ppm/c reference temperature range: C40c to +85c rail-to-rail output amplifier power down package type: 100-lead lqfp (14 mm 14 mm) user interfaces parallel serial (spi?-, qspi?-, microwire?-, dsp-compatible, featuring data readback) i 2 c?-compatible robust 6.5 kv hbm and 2 kv ficdm esd rating integrated functions channel monitor simultaneous output update via ldac clear function to user programmable code amplifier boost mode to optimize slew rate user programmable offset and gain adjust toggle mode enables square wave generation thermal monitor applications variable optical attenuators (voa) level setting (ate) optical micro-electro-mechanical systems (mems) control systems instrumentation functional block diagram figure 1. r r vout dac 0 dac reg0 input reg0 14 14 14 14 14 14 m reg0 c reg0 1.25v/2.5v reference power-on reset 39-to-1 mux r r vout1 vout2 vout3 vout4 vout5 dac 1 dac reg1 input reg1 14 14 14 14 14 14 m reg1 c reg1 r r vout6 dac 6 dac reg6 input reg6 14 14 14 14 14 14 m reg6 c reg6 r r vout7 vout8 dac 7 dac reg7 input reg7 14 14 14 14 14 14 m reg7 c reg7 5 03731-001 fifo + state machine + control logic interface control logic db13/(din/sda) db12/(sclk/scl) db11/(spi/i 2 c) db10 a5 a0 vout0???vout38 reg0 reg1 reset busy clr pd ser/par fifo en cs/(sync/ad0) wr/(dcen/ad1) sdo vout39/mon_out ldac vout38 dvdd (3) dgnd (3) a v dd (5) a gnd (5) dac_gnd (5) refgnd refout/refin signal_gnd (5) ad5380 db0
ad5380 data sheet rev. d | page 2 of 40 table of contents features .............................................................................................. 1 ? integrated functions ........................................................................ 1 ? applications ....................................................................................... 1 ? functional block diagram .............................................................. 1 ? revision history ............................................................................... 3 ? general description ......................................................................... 4 ? specifications ..................................................................................... 5 ? ad5380-5 specifications ............................................................. 5 ? ad5380-3 specifications ............................................................. 7 ? ac characteristics ........................................................................ 8 ? timing characteristics ..................................................................... 9 ? serial interface .............................................................................. 9 ? i 2 c serial interface ...................................................................... 11 ? parallel interface ......................................................................... 12 ? absolute maximum ratings .......................................................... 14 ? esd caution ................................................................................ 14 ? pin configuration and function descriptions ........................... 15 ? terminology .................................................................................... 18 ? typical performance characteristics ........................................... 19 ? functional description .................................................................. 22 ? dac architecturegeneral ..................................................... 22 ? data decoding ............................................................................ 22 ? on-chip special function registers (sfr) ............................ 23 ? sfr commands .......................................................................... 23 ? hardware functions ....................................................................... 26 ? reset function ......................................................................... 26 ? asynchronous clear function .................................................. 26 ? busy and ldac functions...................................................... 26 ? fifo operation in parallel mode ............................................ 26 ? power-on reset .......................................................................... 26 ? power-down ............................................................................... 26 ? ad5380 interfaces .......................................................................... 27 ? dsp-, spi-, microwire-compatible serial interfaces ............ 27 ? i 2 c serial interface ..................................................................... 29 ? parallel interface ......................................................................... 31 ? microprocessor interfacing ....................................................... 32 ? applications information .............................................................. 34 ? power supply decoupling ......................................................... 34 ? power supply sequencing ......................................................... 34 ? typical configuration circuit .................................................. 35 ? ad5380 monitor function ....................................................... 36 ? toggle mode function ............................................................... 36 ? thermal monitor function ....................................................... 37 ? ad5380 in a mems based optical switch ............................. 37 ? optical attenuators .................................................................... 38 ? utilizing the ad5380 fifo ...................................................... 39 ? outline dimensions ....................................................................... 40 ? ordering guide .......................................................................... 40 ?
data sheet ad5380 revision history 5 /14 rev. c to rev. d deleted adsp - 2103 ...................................................... throughout changed adsp - 2101 to adsp - bf 527 ....................... throughout deleted table 1 ; renumbered sequentially ................................... 3 changes to general description section ....................................... 4 changed logic inputs ( except sda/scl), input current parameter, table 1 from 10 a max to 1 a max .................... 5 changed logic inputs ( except sda/scl), input current parameter, table 2 from 10 a max to 1 a max .................... 7 change s to table 4 ............................................................................ 9 change s to table 6 .......................................................................... 12 changes to soft reset section ....................................................... 23 changes to reset function section .............................................. 26 changes to figure 38 ...................................................................... 33 added power supply sequencing section, table 18 , figure 39, and figure 40 ; renumbered sequentially .................................... 34 changed adr280 to adr3412 , typi cal c on figuration circuit section .............................................................................................. 35 added figure 41 and figure 42 ..................................................... 35 9/12 rev. b to rev. c changes to product title .................................................................. 1 changes to general description section and table 1 .................. 3 deleted table 2 ; renumbered sequentially ................................... 3 6/12 rev. a to rev. b changes to features .......................................................................... 1 change s to table 3 ............................................................................ 4 change s to table 4 ............................................................................ 6 changes to output voltage settling time and slew rate parameters, table 5 ........................................................................... 7 changes to t 14 and t 19 parameters, table 6 ..................................... 8 change s to table 9 .......................................................................... 13 changes to figure 10 , figure 11 , and figure 14 ......................... 18 changes to figure 16 , figure 17 , figure 18 , figure 20............... 19 update outline dimensions and changes to ordering guide ....... 38 6 /05 rev. 0 to rev. a changes to specifications ................................................................. 3 changes to terminology ................................................................ 17 change s to table 18 ........................................................................ 24 changes to figure 43 ...................................................................... 35 5/04 revision 0: initial version rev. d | page 3 of 40
ad5380 data sheet general description the ad5380 is a complete, single - supply, 40 - channel, 14 - bit dense dac? available in a 100 - lead lqfp package. all 40 channels have an on - chip output amplifier with rail - to - rail operation. the ad5380 includes a program mable internal 1.25 v/2.5 v, 1 0 ppm/c reference, an on - chip channel monitor function that multiplexes the analog outputs to a common mon_out pin for external monitoring, and an output amplifier boost mode that allows optimization of the amplifier slew rate. the ad5380 contains a double - buffered parallel interface that features a 20 ns wr pulse width, an spi - , qspi - , - microwire, - dsp compatible serial interface with interface speeds in excess of 30 mhz, and an i 2 c - compatible interface that supports a 400 khz data transfer rate. an input register followed by a dac register provides double buffering, allowing the dac outputs to be updated indepen dently or simultaneously using the ldac input. ea ch channel has a programmable gain and offset adjust register that allows the user to fully calibrate any dac channel. power consumption is typically 0.25 ma/channel with boost off. rev. d | page 4 of 40
data sheet ad5380 specifications ad5380 - 5 specifications avdd = 4.5 v to 5.5 v; dvdd = 2.7 v to 5.5 v, agnd = dgnd = 0 v; external refin = 2.5 v; all specifications t min to t max , unless otherwise noted. table 1 . parameter ad5380 - 5 1 unit test conditions/comments accuracy resolution 14 bits relative accuracy (inl) 2 4 lsb max 1 lsb typical differential nonlinearity (dnl) C 1/+2 lsb max guaranteed monotonic by design over temperature zero - scale error 4 mv max offset error 4 mv max measured at code 32 in the linear region offset error tc 5 v/c typ gain error 0.05 % fsr max at 25c 0.06 % fsr max t min to t max gain temperature coefficient 3 2 ppm fsr/c typ dc crosstalk 3 1 lsb max reference input/output reference input 3 reference input voltage 2.5 v 1% for specified performance, avdd = 2 refin + 50 mv dc input impedance 1 m min typically 100 m input current 1 a max typically 30 na reference range 1 to v dd /2 v min/max reference output 4 enabled via cr10 in the ad5380 control register ; cr12 selects the reference voltage output voltage 2.495/2.505 v min/max at ambient, cr12 = 1, optimized for 2.5 v operation 1.22/1.28 v min/max cr12 = 0 reference t c 3 10 ppm max temperature range: +25c to +85c 15 ppm max temperature range: ?40c to +85c output impedance 800 typ output characteristics 3 output voltage range 2 0/avdd v min/max short - circuit current 40 ma max load current 1 ma max capacitive load stability r l = 200 pf max r l = 5 k 1000 pf max dc output impedance 0.6 max monitor pin output impedance 1 k typ three - state leakage current 100 na typ logic inputs (except sda/scl) 3 dvdd = 2.7 v to 5.5 v v ih , input high voltage 2 v min v il , input low voltage dvdd > 3.6 v 0.8 v max dvdd 3.6 v 0.6 v max input current 1 a max total for all pins; t a = t min to t max pin capacitance 10 pf max rev. d | page 5 of 40
ad5380 data sheet parameter ad5380 - 5 1 unit test conditions/comments logic inputs (sda, scl only ) 3 v ih , input high voltage 0.7 dvdd v min smbus compatible at dvdd < 3.6 v v il , input low voltage 0.3 dvdd v max smbus compatible at dvdd < 3.6 v i in , input leakage current 1 a max v hyst , input hysteresis 0. 05 dvdd v min c in , input capacitance 8 pf typ glitch rejection 50 ns max input filtering suppresses noise spikes of less than 50 ns logic outputs ( busy , sdo) 3 v ol , output low voltage 0.4 v max dvdd = 5 v 10%, sinking 200 a v oh , output high voltage dvdd C 1 v min dvdd = 5 v 10%, sourcing 200 a v ol , output low voltage 0.4 v max dvdd = 2.7 v to 3.6 v, sinking 200 a v oh , output high voltage dvdd C 0.5 v min dvdd = 2.7 v to 3.6 v, sourcing 200 a high impedance leakage current 1 a max sdo only high impedance output capacitance 5 pf typ sdo only logic output (sda) 3 v ol , output low voltage 0.4 v max i sink = 3 ma 0.6 v max i sink = 6 ma three - state leakage current 1 a max three - state output capacitance 8 pf typ power requirements avdd 4.5/5.5 v min/max dvdd 2.7/5.5 v min/max power supply sensitivity 3 ? mids cale/ ? v dd C 85 db typ ai dd 0.375 ma/channel max outputs unloaded ; boost o ff; 0.25 ma/channel typ 0.475 ma/channel max outputs unloaded ; boost on ; 0.325 ma/channel typ di dd 1 ma max v ih = dvdd, v il = dgnd ai dd (power - down) 2 0 a max typi cally 1 00 na di dd (power - down) 20 a max typically 1 a power dissipation 80 mw max outputs unloaded, b oost off, avdd = dvdd = 5 v 1 ad5380 - 5 is calibrated using an external 2.5 v reference. temperature range for all versions: C 40c to +85c. 2 accuracy guaranteed from vout= 10 mv to avdd C 50 mv. 3 guaranteed by characterization, not production tested. 4 default on the ad5380 - 5 is 2.5 v. programmable to 1.25 v via cr12 in the ad5380 control register; operating the ad5380 - 5 with a 1.25 v reference will lead to degraded accuracy specifications. rev. d | page 6 of 40
data sheet ad5380 ad5380 - 3 specifications avdd = 2.7 v to 3.6 v; dvdd = 2.7 v to 5.5 v, agnd = dgnd = 0 v; external refin = 1.25 v; all specifications t min to t max , unless otherwise noted. table 2 . parameter ad5380 - 3 1 unit test conditions/comments accuracy resolution 14 bits relative accuracy (inl) 2 4 lsb max differential nonlinearity (dnl) C 1/+2 lsb max guaranteed monotonic over temperature zero - scale error 4 mv max offset error 4 mv max measured at code 64 in the linear region offset error tc 5 v/c typ gain error 0.05 % fsr max at 25c 0.1 % fsr max t min to t max gain temperature coefficient 3 2 ppm fsr/c typ dc crosstalk 3 1 lsb max reference input/output reference input 3 reference input voltage 1.25 v 1% for specified performance dc input impedance 1 m min typically 100 m input current 1 a max typically 30 na reference range 1 to avdd/2 v min/max reference output 4 enabled via cr10 in the ad5380 control register ; cr12 selects the reference voltage output voltage 1.245/1.255 v min/max at ambient; cr12 = 0; optimized for 1.25 v operation 2.47/2.53 v min/max cr12 = 1. reference t c 3 10 ppm/c max temperature range: +25c to +85c 15 ppm/c max temperature range: ?40c to +85c output impedance 800 typ output characteristics 3 output voltage range 2 0/avdd v min/max short - circuit current 40 ma max load current 1 ma max capacitive load stability r l = 200 pf max r l = 5 k 1000 pf max dc output impedance 0.6 max monitor pin output impedance 1 k typ three - state leakage current 100 na typ logic inputs (except sda/scl) 3 dvdd = 2.7 v to 3.6 v v ih , input high voltage 2 v min v il, input low voltage dvdd > 3.6 v 0.8 v max dvdd 3.6 v 0.6 v max input current 1 a max total for all pins; t a = t min to t max pin capacitance 10 pf max logic inputs (sda, scl only ) 3 v ih , input high voltage 0.7 dvdd v min smbus - compatible at dvdd < 3.6 v v il , input low voltage 0.3 dvdd v max smbus - compatible at dvdd < 3.6 v i in , input leakage current 1 a max v hyst , input hysteresis 0.05 dvdd v min c in , input capacitance 8 pf typ glitch rejection 50 ns max input filtering suppresses noise spikes of less than 50 ns rev. d | page 7 of 40
ad5380 data sheet parameter ad5380 - 3 1 unit test conditions/comments logic outputs ( busy , sdo) 3 v ol , output low voltage 0.4 v max sinking 200 a v oh , output high voltage dvdd C 0.5 v min sourcing 200 a high impedance leakage current 1 a max sdo only high impedance output capacitance 5 pf typ sdo only logic output (sda) 3 v ol , output low voltage 0.4 v max i sink = 3 ma 0.6 v max i sink = 6 ma three - state leakage current 1 a max three - state output capacitance 8 pf typ power requirements avdd 2.7/3.6 v min/max dvdd 2.7/5.5 v min/max power supply sensitivity 3 ? midscale/ ?v dd C 85 db typ ai dd 0.375 ma/channel max outputs unloaded; b oost off; 0.25 ma/channel typical 0.475 ma/channel max outputs unloaded; b oost on; 0.325 ma/channel typical di dd 1 ma max v ih = dvdd, v il = dgnd ai dd (power - down) 20 a max typically 100 na di dd (power - down) 20 a max typically 1 a power dissipation 48 mw max outputs unloaded; b oost off, avdd = dvdd = 3 v 1 ad5380 - 3 is calibrated using an external 1.25 v reference. temperature range is C 40c to +85c. 2 accuracy guaranteed from vout = 10 mv to avdd C 50 mv. 3 guaranteed by characterization, not production tested. 4 default on the ad5380 - 3 is 1.25 v. programmable to 2.5 v via cr12 in the ad5380 control register; operating the ad5380 - 3 with a 2.5 v reference will lead to degraded accuracy specifications and limited input code range. ac characteristics 1 avdd = 2.7 v to 3.6 v or 4.5 v to 5.5 v; dvdd = 2.7 v to 5.5 v; agnd = dgnd = 0 v. table 3 . parameter all unit test conditions/comments dynamic performance output voltage settling time 2 1/4 scale to 3/4 scale change settling to 1 lsb 3 s typ boost mode off, cr11 = 0 8 s max boost mode off, cr11 = 0 slew rate 2 1.5 v/s typ boost mode off, cr11 = 0 2.5 v/s typ boost mode on, cr11 = 1 digital - to - analog glitch energy 12 nv - s typ glitch impulse peak amplitude 15 mv typ dac - to - dac crosstalk 1 nv - s typ see terminology section digital crosstalk 0.8 nv - s typ digital feedthrough 0.1 nv - s typ effect of input bus activity on dac output under test output noise 0.1 hz to 10 hz 15 v p - p typ external reference, midscale loaded to dac 40 v p - p typ internal reference, midscale loaded to dac output noise spectral density at 1 khz 150 nv/hz typ at 10 khz 100 nv/hz typ 1 guaranteed by design and characterization, not production tested. 2 the slew rate can be programmed via the cu rrent boost control bit (cr11) in the ad5380 control register. rev. d | page 8 of 40
data sheet ad5380 timing characteristi cs serial interface dvdd = 2.7 v to 5.5 v ; avdd = 4.5 v to 5.5 v or 2.7 v to 3.6 v; agnd = dgnd = 0 v; all specifications t min to t max , unless otherwise noted . table 4 . parameter 1 , 2 , 3 limit at t min , t max unit description t 1 33 ns min sclk cycle time t 2 13 ns min sclk high time t 3 13 ns min sclk low time t 4 13 ns min sync falling edge to sclk falling edge setup time t 5 4 13 ns min 24 th sclk falling edge to sync falling edge t 6 4 33 ns min minimum sync low time t 7 10 ns min minimum sync high time t 7a 140 ns min minimum sync high time in readback mode t 8 5 ns min data setup time t 9 4.5 ns min data hold time t 10 4 36 ns max 24th sclk falling edge to busy falling edge t 11 670 ns max busy pulse width low (single channel update) t 12 4 20 ns min 24th sclk falling edge to ldac falling edge t 13 20 ns min ldac pulse width low t 14 100/2000 ns min/max busy rising edge to dac output response time t 15 0 ns min busy rising edge to ldac falling edge t 16 100 /2000 ns min /max ldac falling edge to dac output response time t 17 3 s typ dac output settling time; boost mode off t 18 20 ns min clr pulse width low t 19 40 s max clr pulse activation time t 20 5 30 ns max sclk rising edge to sdo valid t 21 5 5 ns min sclk falling edge to sync rising edge t 22 5 8 ns min sync rising edge to sclk rising edge t 23 20 ns min sync rising edge to ldac falling edge 1 guaranteed by design and characterization, not production tested. 2 all input signals are specified with tr = tf = 5 ns (10% to 90 % of vcc), and are timed from a voltage level of 1.2 v. 3 see figure 2 , figure 3 , figure 4 , and figure 5 . 4 standalone mode only. 5 daisy - chain mode only. figure 2 . load circuit for digital output timing c l 50pf to output pin v oh (min) or v ol (max) 200a 200a i ol i oh 03731-002 rev. d | page 9 of 40
ad5380 data sheet figure 3 . serial interface timing diagram (standalone mode) figure 4 . serial interface timing diagram (data readback mode) figure 5 . serial interface timing diagram (daisy - cha in mode) 1 ldac active during busy. 2 ldac active after busy. busy sync ldac 1 ldac 2 clr vout vout2 vout1 din sclk 03731-003 t 7 t 8 t 9 t 4 t 3 t 1 t 2 t 5 t 17 t 17 t 12 t 13 t 18 t 19 t 16 t 14 t 10 t 15 t 13 t 11 t 6 db0 db23 24 24 t 7a 24 48 sclk sync din sdo db23 db0 db23 db0 db23 db0 input word specifies register to be read undefined nop condition selected register data clocked out 03731-004 t 22 t 13 t 23 t 21 t 2 t 3 t 20 t 8 t 9 t 7 t 4 t 1 sclk sync sdo din ldac 48 24 db23 db0 db0 db23 db23 db0 input word for dac n input word for dac n+1 undefined input word for dac n 03731-005 rev. d | page 10 of 40
data sheet ad5380 i 2 c serial interface dvdd = 2.7 v to 5.5 v; avdd = 4.5 v to 5.5 v or 2.7 v to 3.6 v; agnd = dgnd = 0 v; all specifications t min to t max , unless otherwise noted. table 5 . parameter 1 , 2 limit at t min , t max unit description f scl 400 khz max scl clock frequency t 1 2.5 s min scl cycle time t 2 0.6 s min t high , scl high time t 3 1.3 s min t low , scl low time t 4 0.6 s min t hd,sta , start/repeated start condition hold time t 5 100 ns min t su, dat , data setup time t 6 3 0.9 s max t hd, dat , data hold time 0 s min t hd, dat , data hold time t 7 0.6 s min t su,sta , setup time for repeated start t 8 0.6 s min t su,sto , stop condition setup time t 9 1.3 s min t buf , bus free time between a stop and a start condition t 10 300 ns max t r , rise time of scl and sda when receiving 0 ns min t r , rise time of scl and sda when receiving (cmos compatible) t 11 300 ns max t f , fall time of sda when transmitting 0 ns min t f , fall time of sda when receiving (cmos compatible) 300 ns max t f , fall time of scl and sda when receiving 20 + 0.1c b 4 ns min t f , fall time of scl and sda when transmitting c b 400 pf max capacitive load for each bus line 1 guaranteed by design and characterization, not pro duction tested. 2 see figure 6 . 3 a master device must provide a hold time of at least 300 ns for the sda signal (referred to the vih min of the scl sig nal) in order to bridge the undefined region of scls falling edge. 4 cb is the total capacitance, in pf, of one bus line. tr and tf are measured between 0.3 dvdd and 0.7 dvdd. figure 6. i 2 c compatible serial interface timing diagram start condition repeated start condition stop condition t 9 t 3 t 1 t 11 t 4 t 10 t 4 t 5 t 7 t 6 t 8 t 2 sda scl 03731-006 rev. d | page 11 of 40
ad5380 data sheet parallel interface dvdd = 2.7 v to 5.5 v; avdd = 4.5 v to 5.5 v or 2.7 v to 3.6 v; agnd = dgnd = 0 v; all specifications t min to t max , unless otherwise noted. table 6 . parameter 1 , 2 , 3 limit at t min , t max unit description t 0 4.5 ns min reg0, reg1, address to wr rising edge setup time t 1 4.5 ns min reg0, reg1, address to wr rising edge hold time t 2 20 ns min cs pulse width low t 3 20 ns min wr pulse width low t 4 0 ns min cs to wr falling edge setup time t 5 0 ns min wr to cs rising edge hold time t 6 4.5 ns min data to wr rising edge setup time t 7 4.5 ns min data to wr rising edge hold time t 8 20 ns min wr pulse width high t 9 4 700 ns min minimum wr cycle time (single - channel write) t 10 30 ns max wr rising edge to busy falling edge t 11 4 670 ns max busy pulse width low (single - channel update) t 12 30 ns min wr rising edge to ldac falling edge t 13 20 ns min l dac pulse width low t 14 100 /2000 ns min/ max busy rising edge to dac output response time t 15 20 ns min ldac rising edge to wr rising edge t 16 0 ns min busy rising edge to ldac falling edge t 17 100 /2000 ns min /max ldac falling edge to dac output response time t 18 8 s typ dac output settling time t 19 20 ns min clr pulse width low t 20 40 s max clr pulse activation time 1 guaranteed by design and characterization, not production tested. 2 all inp ut signals are specified with t r = t r = 5 ns (10% to 90% of dvdd) and timed from a voltage level of 1.2 v. 3 see figure 7 . 4 see figure 29. rev. d | page 12 of 40
data sheet ad5380 figure 7 . parallel interface timing diagram t 18 t 18 t 19 t 20 t 13 t 3 t 2 t 8 t 13 t 11 t 9 t 12 t 0 t 1 t 15 t 7 t 6 t 17 t 16 t 10 t 14 t 4 t 5 reg0, reg1, a5...a0 cs wr db13...db0 busy ldac 1 vout1 vout2 clr vout ldac 2 1 ldac active during busy. 2 ldac active after busy. 03731-007 rev. d | page 13 of 40
ad5380 data sheet absolute maximum rat ings t a = 25c, unless otherwise noted 1 . table 7 . parameter rating avdd to agnd C 0.3 v to +7 v dvdd to dgnd C 0.3 v to +7 v digital inputs to dgnd C 0.3 v to dvdd + 0.3 v sda/scl to dgnd C 0.3 v to + 7 v digital outputs to dgnd C 0.3 v to dvdd + 0.3 v refin/refout to agnd C 0.3 v to avdd + 0.3 v agnd to dgnd C 0.3 v to +0.3 v voutx to agnd C 0.3 v to avdd + 0.3 v analog inputs to agnd C 0.3 v to avdd + 0.3 v operating temperature range commercial (b version) C 40c to +85c storage temperature range C 65c to +150c junction temperature (t j max ) 150c 100 - lead lqfp package ja thermal impedance 44c/w reflow soldering peak temperature 230c esd hbm 6.5 kv ficdm 2 kv stresses above those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. exposure to absolute maxi - mum rating conditions for extended periods may affect device reliability. esd caution 1 transient currents of up to 100 ma will not cause scr latch - up . rev. d | page 14 of 40
data sheet ad5380 pin configuration an d function descripti ons figure 8 . 100- lead lqfp pin configuration table 8 . pin function descriptions mnemonic function voutx buffered analog outputs for channel x. each analog output is driven by a rail -to - rail output amplifier operating at a gain of 2. each output is capable of driving an output lo ad of 5 k to ground. typical output impedance is 0.5 . signal_gnd(1 C 5) analog ground reference points for each group of eight output channels. all signal_gnd pins are tied together internally and should be connected to the agnd plane as close as possible to the ad538 0 . dac_gnd(1 C 5) each group of eight channels contains a dac_gnd pin. this is the ground reference point for the inter nal 14 - bit dac. these pins shoul d be connected to the agnd plane. agnd(1 C 5) analog ground reference point. each group of eight channels contains an agnd pin. all agnd pins should be connected externally to the agnd plane. avdd(1 C 5) analog supply pins. each group of eight channels has a separate avdd pin. these pins are shorted internally and should be decoupled with a 0.1 f ceramic cap acitor and a 10 f tantalum capacitor. operating range for the ad5380 -5 is 4.5 v to 5.5 v; operating range for the ad5380 -3 is 2.7 v to 3.6 v. dgnd ground for all digital circuitry. dvdd logic power supply. guaranteed operating range is 2.7 v to 5.5 v. it is recommended that these pins be decoupled with 0.1 f ceramic and 10 f tantalum capacitors to dgnd. refgnd ground reference point for the internal reference. refout/refin the ad5380 contains a common refout/refin pin. when the internal reference is selected, this pin is the reference output. if the application require s an external reference, it can be applied to this pin and the internal reference can be disabled via the control register. the default for this pin is a reference input. reset db7 db6 db5 db4 db3 db2 db1 db0 reg0 reg1 vout23 vout22 vout21 vout20 avdd3 agnd3 dac_gnd3 signal_gnd3 vout19 vout18 vout17 vout16 avdd2 agnd2 5 9 7 4 7 5 6 9 7 0 7 1 7 2 6 7 6 8 6 6 7 3 6 4 6 5 6 0 6 1 6 2 6 3 5 7 5 8 5 5 5 6 5 3 5 4 5 2 5 1 signal_gnd5 dac_gnd5 agnd5 avdd5 vout5 vout6 vout7 vout32 vout33 vout34 vout35 vout36 vout37 vout38 vout39/mon_out vout8 vout9 vout10 vout11 vout12 dac_gnd2 signal_gnd2 vout13 vout14 vout15 26 28 27 29 30 32 33 34 35 36 31 37 38 39 40 42 43 44 45 41 46 47 48 49 50 cs/(sync/ad0) db13/(din/sda) db12/(sclk/scl) db11/(spi/i 2 c) db10 db9 db8 sdo(a/b) dvdd dgnd dgnd a5 a4 a3 a2 a1 a0 dvdd dvdd dgnd ser/par pd wr (dcen/ad1) ldac busy 100 98 99 97 96 95 94 92 91 90 89 88 87 93 86 85 84 82 81 80 79 78 77 76 83 5 4 3 2 7 6 9 8 1 1 4 1 3 1 2 1 1 1 6 1 5 1 7 1 0 1 9 1 8 2 3 2 2 2 1 2 0 2 4 2 5 fifo en clr vout24 vout25 vout26 v o u t 2 7 signal_gnd4 dac_gnd4 agnd4 avdd4 vout28 vout29 vout30 vout31 refgnd refout/refin signal_gnd1 dac_gnd1 avdd1 vout0 vout1 vout2 vout3 vout4 agnd1 pin 1 identifier ad5380 top view (not to scale) 03731-008 rev. d | page 15 of 40
ad5380 data sheet mnemonic function vout39/mon_out this pin h as a dual function. it acts a buffered output for channel 39 in default mode. however, when the monitor function is enabled, this pin acts as the output of a 39 -to - 1 channel multiplexer that can be programmed to multiplex one of channels 0 to 38 to the mon_out pin. the mon_out pins ou tput impedance is typically 500 and is intended to drive a high input impedance like that exhibited by sar adc inputs. ser/ par interface select input. this pin allows the user to select whether the serial or parallel interface will be used. if it is tied high, the serial interface mode is selected and pin 97 ( spi /i 2 c) is used to determine if the interface mode is spi or i 2 c. parallel interface mode is selected when ser/ par is low. cs /( sync /ad0) in parallel interface mode, this pin acts as chip select input (level sensitive, active low). when low, the ad5380 is selected. serial interface mode. this is the frame synchronization input signal for the serial clocks before the addressed register is updated. i 2 c mode. this pin acts as a hardware address pin used in conjunction with ad1 to determine the software address for the device on the i 2 c bus. wr /(dcen/ ad1) multifunction pin. in parallel interface mode, this pin acts as write enable. in serial interface mode, this pin acts as a daisy - chain enable in spi mode and as a hardware address pin in i 2 c mode. parallel i nterface write input (edge sensitive). the rising edge of wr is used in conjunction with cs low and the address bus inputs to write to the selected device registers. serial interface. daisy - chain select input (level sen sitive, active high). when high, this signal is used in conjunction with ser/ par high to enable the spi serial interface daisy - chain mode. i 2 c mode. this pin acts as a hardware address pin used in conjunction with ad0 t o determine the software address for this device on the i 2 c bus. db13 C db0 parallel data bus. db13 is the msb and db0 is the lsb of the input data - word on the ad5380 . a5 C a0 parallel address inputs. a5 to a0 are decoded to address one of the ad5380 s 40 input channels. used in conjunction with the reg1 and reg0 pins to determine the destination register for the input data. reg1, reg0 in parallel interface mode, reg1 and reg0 are used in decoding the destination registers for the input data. reg1 and reg0 are decoded to address the input data register, offset register, or gain register for the selected channel and to d ecide the special function registers. sdo/( a /b) serial data output in serial interface mode. three - stateable cmos output. sdo can be used for daisy - chaining a number of devices together. data is clocked out on sdo on the rising edge of s clk, and is valid on the falling edge of sclk. when operating in parallel interface mode, this pin acts as the a or b data register select when writing data to the ad5380 s data registers with to ggle mode selected (see the toggle mode function section). in toggle mode, the ldac is used to switch the output between the data conta ined in the a and b data registers. all dac channels contain two data registers. in normal mode, data register a is the default for data transfers. busy digital cmos output. busy goes low during internal calculations o f the data (x2) loaded to the dac data register. during this time, the user can continue writing new data to the x1, c, and m registers, but no further updates to the dac registers and dac outputs can take place. if ldac is taken low whil e busy is low, this event is stored. busy also goes low during power - on reset, and when the busy pin is low. during this time, the interface is disabled and any events on ldac are ignored. a clr operation also brings busy low. ldac load dac logic input (active low). if ldac is taken low while busy is inactive (high), the contents of the input registers are transferred to the dac registers and the dac outputs are updated. if ldac is taken low while busy is active and internal calculations are taking place, the ldac event is stored and t he dac registers are updated when busy goes inactive. however , any events on ldac during power - on reset or on reset are ignored. clr asynchronous clear input. the clr input is falling edge sensitive. when clr is activated, all channels are updated with the data contained in the clr code register. busy is low for a duration of 35 s while all channe ls are being updated with the clr code. reset asynchronous digital reset input (falling edge sensitive). the function of this pin is equivalent to that of the power - on reset generator. when this pin is taken low, the s tate machine initiates a reset sequence to digitally reset the x1, m, c, and x2 registers to their default power - on values. this sequence typically takes 270 s. the falling edge of reset initiates the reset process and busy goes low for the duration, returning high when reset is complete. while busy is low, all interfaces are disabled and all ldac pulses are ignored. when busy retur ns high, the part resumes normal operation, and the status of the reset pin is ignored until the next falling edge is detected. pd power down (level sensitive, active high). pd is used to place the device in low power mode, where ai dd r educes to 2 a and di dd to 20 a. in power - down mode, all internal analog circuitry is placed in low power mode, and the analog output will be configured as a high impedance output or will provide a 100 k load to ground, depending on how the power - down mo de is configured. the serial interface remains active during power - down. rev. d | page 16 of 40
data sheet ad5380 mnemonic function fifo en fifo enable (level sensitive, active high). when connected to dvdd, the internal fifo is enabled, allowing the user to write to the device at full speed. fifo is only available in parallel interface mode. the status of the fifo en pin is sampled on power -u p, and also following a clear or reset , to determine if the fifo is enabled. in either serial or i 2 c interface modes, the fifo en pin should be tied low. db11/( spi /i 2 c) multifunction input pin. in parallel interface mode, this pin acts as db11 of the parallel input data - word. in serial interface mode, this pin acts as serial interface mode select. when serial interface mode is selected (ser/ par = 1) and this input is low, spi mode is selected. in spi mode, db12 is the serial clock (sclk) input and db13 is the serial data (din) input. when serial interface mode is selected (ser/ par = 1) and this input is high, i 2 c mode is selected. in this mo de, db12 is the serial clock (scl) input, and db13 is the serial data (sda) input. db12/(sclk/scl) multifunction input pin. in parallel interface mode, this pin acts as db12 of the parallel input data - word. in serial interface mode, this pi n acts as a serial clock input. serial interface mode. in serial interface mode, data is clocked into the shift register on the falling edge of sclk. this operate s at clock speeds up to 30 mhz. i 2 c mode. in i 2 c mode, this pin performs the scl function, clocking data i nto the device. the data transfer rate in i 2 c mode is compatible with both 100 khz and 400 khz operating modes. db13/(din/sda) multifunction data input pin. in parallel interface mode, this pin acts as db13 of the parallel input data - word. serial interf ace mode. in serial interface mode, this pin acts as the serial data input. da ta must be valid on the falling edge of sclk. i 2 c mode. in i 2 c mode, this pin is the serial data pin (sda) operating as an open - drain input/output. rev. d | page 17 of 40
ad5380 data sheet terminology relative accuracy relative accuracy , or endpoint linearity , is a measure of the maximum deviation from a straight line passing through the endpoints of the dac transfer function. it is measured after adjusting for z ero - scale error and full - scale error, and is expressed in lsb. differential nonlinearity differential nonlinearity is the difference between the measured change and the ideal 1 lsb change between any two adjacent codes. a specified differential nonlinearit y of 1 lsb maximum ensures monotonicity. zero - scale error zero - scale error is the error in the dac output voltage when all 0s are loaded into the dac register. ideally, with all 0s loaded to the dac and m = all 1s, c = 2 n C 1 vout ( zero - scale ) = 0 v zero - scale error is a measure of the difference between vout (actual) and vout (ideal), expressed in mv. it is mainly due to offsets in the output amplifier. offset error offset error is a measure of the difference between vout (actual) and vout (ideal) in the linear region of the transfer function, expressed in mv. offset error is measured on the ad5380 - 5 with code 32 loaded into the dac register, and on the ad5380 - 3 with code 64. gain error gain error is specified in the linear region of the output range between vout= 10 mv and vout = avdd C 5 0 m v. it i s t h e deviation in slope of the dac transfer characteristic from the ideal and is expre ssed in %fs r with the dac output unloaded. dc crosstalk this is the dc change in the output level of one dac at midscale in response to a full - scale code (all 0s to all 1s, and vice versa) and output change of all other dacs. it is expressed in lsb. dc out put impedance this is the effective output source resistance. it is dominated by package lead resistance. voltage settling time this is the amount of time it takes for the output of a dac to settle to a specified level for a ? to ? full - scale input change , and is measured from the busy rising edge. digital -to - analog glitch energy this is the amount of energy injected into the analog output at the major code transition. it is specified as the area of the glitch in nv - s. it is measured by t oggling the dac register data between 0x1fff and 0x2000. dac -to - dac crosstalk dac - to - dac crosstalk is the glitch impulse that appears at the output of one dac due to both the digital change and the subsequent analog output change at another dac. the victim channel is loaded with midscale. dac - to - dac crosstalk is specified in nv - s. digital crosstalk the glitch impulse transferred to the output of one converter due to a change in the dac register code of another converter is defined as the digital crosstalk and is specified in nv - s. digital feedthrough when the device is not selected, high frequency logic activity on the devices digital inputs can be capacitively coupled both across and through the device to show up as noise on the vout pins. it can also be coupled along the supply and ground lines. this noise is digital feedthrough. output noise spectral density this is a measure of internally generated random noise. random noise is characterized as a spectral density (voltage per hertz). it is measured by loading all dacs to midscale and measuring noise at the output. it is measured in nv/hz in a 1 hz bandwidth at 10 khz. rev. d | page 18 of 40
data sheet ad5380 typical performance characteristics figure 9 . typical ad5380 -5 inl plot figure 10 . ad5380 -5 glitch impulse figure 11 . slew rate with boost off figure 12 . typical ad5380 -3 inl plot figure 13. refout temperature coefficient figure 14 . slew rate with boost on 03731-009 input code 16384 0 4096 8192 12288 inl error (lsb) ?2.0 2.0 1.5 1.0 0.5 0 ?0.5 ?1.0 ?1.5 avdd = dvdd = 5.5v v ref = 2.5v t a = 25c 2.510 2.505 2.500 2.995 2.990 0 12 10 8 6 4 2 voltage (v) time (s) 03731-103 03731-105 ldac vout avdd = dvdd = 5v vref = 2.5v t a = 25c 03731-012 input code 16384 0 4096 8192 12288 inl error (lsb) ?2.0 2.0 1.5 1.0 0.5 0 ?0.5 ?1.0 ?1.5 avdd = dvdd = 3v v ref = 1.25v t a = 25c 03731-013 reference drift (ppm/c) ?5.0 ?1.5 2.5 ?3.5?4.5 ?4.0 0.5?0.5 3.5 ?2.5 1.5 ?1.0 3.0 ?3.0 1.00 4.0 5.0 4.5 ?2.0 2.0 frequency 0 40 30 20 35 25 15 10 5 03731-106 ldac vout avdd = dvdd = 5v vref = 2.5v t a = 25c rev. d | page 19 of 40
ad5380 data sheet rev. d | page 20 of 40 figure 15. ai dd histogram with boost off figure 16. di dd histogram figure 17. exiting soft power down figure 18. ad5380 power-up transient figure 19. inl distribution figure 20. exiting hardware power down 03731-015 ai dd (ma) 11 8910 percentage of units (%) 14 12 10 8 6 4 2 avdd = 5.5v v ref = 2.5v t a = 25c 03731-107 di dd (ma) 0.9 1.0 0.5 0.6 0.7 0.8 number of units 0 10 8 6 4 2 dvdd = 5.5v v ih = dvdd v il = dgnd t a = 25c 03731-100 busy vout avdd = dvdd = 5v vref = 2.5v t a = 25c 03731-102 vdd vout avdd = dvdd = 5v vref = 2.5v t a = 25c 03731-019 inl error distribution (lsb) 2 ?2 ?1 0 1 number of units 0 14 12 10 8 6 4 2 avdd = 5.5v refin = 2.5v t a = 25c 03731-101 pd vout avdd = dvdd = 5v vref = 2.5v t a = 25c
data sheet ad5380 figure 21 . ad5380 - 5 output amplifier source and sink capability figure 22 . headroom at rails vs. source/sink current figure 23 . refout noise spectral density figure 24 . ad5380 - 3 output amplifier source and sink capability figure 25 . adjacent channel dac - to - dac crosstalk figure 26 . 0.1 hz to 10 hz noise plot 03731-021 current (ma) ?40 ?20 ?10 ?5 ?2 0 2 5 10 20 40 vout (v) ?1 6 4 3 2 5 1 0 zero scale 1/4 scale midscale 3/4 scale ful l scale a vdd = dvdd = 5v v ref = 2.5v t a = 25c 03731-022 i source /i sink (ma) 2.00 0 0.25 0.50 0.75 1.00 1.25 1.50 1.75 error voltage (v) ? 0.20 0.20 0.10 0.05 0.15 0 ? 0.05 ? 0.10 ? 0.15 avdd = 5v v ref = 2.5v t a = 25 c error at zero sinking current (vdd ? vout) at full-scale sourcing current 03731-023 frequency (hz) 100k 100 1k 10k output noise (nv/ hz) 0 600 500 400 300 200 100 avdd = 5v t a = 25 c refout decoupled with 100nf capacitor refout = 2.5v refout = 1.25v 03731-024 current (ma) ?40 ?20 ?10 ?5 ?2 0 2 5 10 20 ?40 vout (v) ?1 6 4 3 2 5 1 0 zero scale 1/4 scale midscale 3/4 scale ful l scale a vdd = dvdd = 3v v ref = 1.25v t a = 25c 03731-025 sample number 550 0 100 150 200 250 300 50 350 400 500 450 amplitude (v) 2.449 2.456 2.455 2.454 2.453 2.452 2.451 2.450 avdd = dvdd = 5v v ref = 2.5v t a = 25 c 14ns/sample number av dd = dv dd = 5v v ref = 2.5v t a = 25 c exits soft pd to midscale 03731-026 avdd = dvdd = 5v t a = 25 c dac loaded with midscale external reference y axis = 5 v/div x axis = 100ms/div rev. d | page 21 of 40
ad5380 data sheet functional descripti on dac architecture general the ad5380 is a complete, single - supply, 40 - channel voltage output dac that offers 14 - bit resolution. the part is available in a 100 - lead lqfp package and features both a parallel and a serial interface. this product includes an internal, software selectable, 1.25 v/2.5 v, 10 ppm/c reference that can be used to drive the buffered reference inputs; alternatively, an external reference can be used to drive these inputs. internal/external reference selection is via the cr10 bit in the control register; cr12 selects the reference magnitude if the internal reference is rail - to - rail output capable of driving 5 k? in parallel with a 200 pf load. figur e 27 . single - channel architecture the architecture of a single dac channel consists of a 14 - bit resistor - string dac followed by an output buffer amplifier operating at a gain of 2 . this resistor - string architecture guaran - tees dac monotonicity. the 14 - bit binary digital code loaded to the dac register determines at what node on the string the voltage is tapped off before being fed to the output amplifier. each channel on these devices contains independent offset and gain control reg isters that allow the user to digitally trim offset and gain. these registers give the user the ability to calibrate out errors in the complete signal chai n, including the dac, using the internal m and c registers, which hold the correction factors. all c hannels are double buffered, allowing synchronous updat - ing of all channels using the ldac pin. figur e 27 shows a block diagram of a single channel on the ad5380 . the digital input transfer function for each dac can be represented as x2 = [( m + 2)/ 2 n x1 ] + ( c C 2 n C 1 ) where: x2 is the data - word loaded to the resistor string dac . x1 is the 14 - bit data - word written to the dac input register . m is the gain coefficient (default is 0x3ffe on the ad5380 ). the gain coefficient is written to the 13 most significant bits (db 13 to db 1 ) and the lsb (db 0 ) is zero. n = dac resolution ( n = 14 for ad5380 ) . c is the14 - bit offset coe fficient (default is 0x2000). the complete transfer function for these devices can be represented as v out = 2 v ref x2 /2 n x2 is the data - word loaded to the resistor string dac. v ref is the internal reference voltage or the reference voltage externally applied to the dac refout/refin pin. for specified performance, an external reference voltage of 2.5 v is recom - mended for the ad5380 - 5 , and 1.25 v for the ad5380 - 3 . data decoding the ad5380 contains a 14 - bit data bus, db13 to db0. depend - ing on the value of reg1 and reg0 (see ta bl e 1 ), this data is loaded into the addressed dac input registers, offset (c) registers, or gain (m) registers. the format data, offset (c), and gain (m) register contents are shown in table 10 to table 12. table 9 . register selection reg1 reg0 register selected 1 1 input data register (x1) 1 0 offset register (c) 0 1 gain register (m) 0 0 special function registers (sfrs) table 10 . dac data format (reg1 1, reg0 1) db13 to db0 dac output (v) 11 1111 1111 1111 2 v ref (16383/16384) 11 1111 1111 1110 2 v ref (16382/16384) 10 0000 0000 0001 2 v ref (8193/16384) 10 0000 0000 0000 2 v ref (8192/16384) 01 1111 1111 1111 2 v ref (8191/16384) 00 0000 0000 0001 2 v ref (1/16384) 00 0000 0000 0000 0 table 11 . offset data format (reg1 1, reg0 0) db13 to db0 offset (lsb) 11 1111 1111 1111 +8191 11 1111 1111 1110 +8190 10 0000 0000 0001 +1 10 0000 0000 0000 0 01 1111 1111 1111 C 1 00 0000 0000 0001 C 8191 00 0000 0000 0000 C 8192 table 12 . gain data format (reg1 0, reg0 1) db13 to db0 gain factor 11 1111 1111 1110 1 10 1111 1111 1110 0.75 01 1111 1111 1110 0.5 00 1111 1111 1110 0.25 00 0000 0000 0000 0 03731-027 vout r r 14-bit dac dac reg m reg c reg 1 input reg 2 input data v ref avdd rev. d | page 22 of 40
data sheet ad5380 on - chip special functio n registers (sfr) the ad5380 contains a number of special function registers (sfrs), as outlined in table 13 . sfrs are addressed with reg1 = reg0 = 0 and are decoded using address b its a5 to a0. table 13 . sfr register functions (reg1 = 0, reg0 = 0) r/ w a5 a4 a3 a2 a1 a0 function x 0 0 0 0 0 0 nop (no operation) 0 0 0 0 0 0 1 write clr code 0 0 0 0 0 1 0 soft clr 0 0 0 1 0 0 0 soft power - down 0 0 0 1 0 0 1 soft power - up 0 0 0 1 1 0 0 control register write 1 0 0 1 1 0 0 control register read 0 0 0 1 0 1 0 channel monitor 0 0 0 1 1 1 1 soft reset sfr commands nop (no operation) reg1 = reg0 = 0, a5 to a0 = 000000 performs no operation, but is useful in serial readback mode to clock out data on d out for diagnostic purposes. busy pulses low during a nop operation. write clr code reg 1 = reg 0 = 0 , a 5 C a 0 = 000001 db13 to db0 = contain the clr data bringing the clr line low or exercising the soft clear function will load the contents of the dac registers with the data con - tained in the user configurable clr register, and will set vout0 to vout39 accord ingly. this can be very useful for setting up a specific output voltage in a clear condition. it is also beneficial for calibration purposes; the user can load full scale or zero scale to the clear code register and then issue a hard - ware or software clear to load this code to all dacs, removing the need for individual writes to each dac. default on power - up is all zeros. soft clr reg1 = reg0 = 0, a5 to a 0 = 000010 db13 to db0 = dont care executing this instruction performs the clr, which is func - tionally the same as that provided by the external clr pin. the dac outputs are loaded with the data in the clr code register. it takes 35 s to fully execute the soft clr, as indicated by the busy low time. soft power - down reg1 = reg0 = 0, a5 to a 0 = 001000 db13 to db0 = dont care executing this instruction performs a global power - down feature that puts all channels into a low power mode that reduces the analog supply current to 2 a max and the digital current to 20 a max. in power - down mode, the output amplifier can be configured as a high impedance output or can provide a 100 k? load to ground. the contents of all internal registers are retained in power - down mode. no register can be written to while in power - down. soft powe r - up reg1 = reg0 = 0, a5 to a 0 = 001001 db13 to db0 = dont care this instruction is used to power up the output amplifiers and the internal reference. the time to exit power - down is 8 s. the hardware power - down and software function are internally combin ed in a digital or function. soft reset reg1 = reg0 = 0, a5 to a 0 = 001111 db13 to db0 = dont care this instruction is used to implement a software reset. all internal registers are reset to their default values, which correspond to m at full scale and c at zero scale . the contents of the dac registers are cleared, setting all analog outputs to 0 v. the soft reset activation time is 135 s. only perform a soft reset when the ad5380 is not in power - down mode. rev. d | page 23 of 40
ad5380 data sheet table 14 . control register contents msb lsb cr13 cr12 cr11 cr10 cr9 cr8 cr7 cr6 cr5 cr4 cr3 cr2 cr1 cr0 control register write/read reg1 = reg0 = 0, a5 to a0 = 001100, r/ w status determines if the operation is a write (r/ w = 0) or a read (r/ w = 1). db13 to db0 contains the control register data. control register contents cr13: power - down status. this bit is used to configure the output amplifier state in power down. cr13 = 1. amplifier output is high impedance (default on power - up). cr13 = 0. amplifier output is 100 k? to ground. cr12: ref select. this bit selects the operating internal r eference for the ad5380 . cr12 is programmed as follows: cr12 = 1: internal reference is 2.5 v ( ad5380 - 5 default) , the recommended operat ing reference for ad5380 - 5 . cr12 = 0: internal reference is 1.25 v ( ad5380 - 3 default), the recommended operating reference for ad5380 - 3 . cr11: current boost control. this bit is used to boost the current in the output amplifier, thereby altering its slew rate. this bit is configured as follows: cr11 = 1: boost mode on. this maximizes the bias current in the output amplifier, optimizing its slew rate but increasing the power dissipation. cr11 = 0: boost mode off (default on power - up). this reduces the bias current in the output amplifier and reduces the overall power consumpti on. cr10: internal/external reference. this bit determines if the dac uses its internal reference or an externally applied reference. cr10 = 1: internal reference enabled. the reference output depends on data loaded to cr12. cr10 = 0: external reference se lected (default on power - up). cr9: channel monitor enable (see channel monitor function ). cr9 = 1: monitor enabled. this enables the channel monitor fun ction. after a write to the monitor channel in the sfr register, the selected channel output is routed to the mon_out pin. vout39 operates as the mon_out pin. cr9 = 0: monitor disabled (default on power - up). when the monitor is disabled, the mon_out pin as sumes its normal dac output function. cr8: thermal mo nitor function. this function is used to monitor the ad5380 s internal die temperature when enabled. the thermal monitor powers down the outp ut amplifiers when the temperature exceeds 130c. this function can be used to protect the device in cases where power dissipation may be exceeded if a number of output channels are simultaneously short - circuited. a soft power - up will re - enable the output amplifiers if the die temperature has dropped below 130c. cr8 = 1: thermal monitor enabled. cr8 = 0: thermal monitor disabled (default on power - up). cr7: dont care. cr6 to cr2: toggle function enable. this function allows the user to toggle the output between two codes loaded to the a and b register s for each dac. control register bits cr6 to cr2 are used to enable individual groups of eight channels for operation in toggle mode. a logic 1 written to any bit enables a group of channels; a logic 0 disabl es a group. ldac is used to toggle between the two registers. table 15 shows the decoding for tog gle mode operation. for example, cr6 controls group w, which contains c hannel 32 to channel 39, cr6 = 1 enables these channels . cr1 and cr0: dont care. table 15. cr bit group channels cr6 4 32 C 39 cr5 3 24 C 31 cr4 2 16 C 23 cr3 1 8 C 15 cr2 0 0 C 7 channel monitor function reg1 = reg0 = 0, a5 to a0 = 001010 db13 to db8 = contain data to address the monitored channel. a channel monitor function is provided on the ad5380 . this feature, which consists of a multiplexer addressed via the inter - face, allows any channel output to be routed to the mon_out pin for monitoring using an external adc. in channel monitor mode, vout39 becomes the mon_out pin, to which all monitored pins are routed. the channel monitor function must be enabled in the contr ol register before any channels are routed to mon_out. on the ad5380 , db13 to db8 contain the channel address for the monitored channel. selecting channel address 63 three - states mon_out. rev. d | page 24 of 40
data sheet ad5380 table 16. ad5380 channel monitor decoding reg1 reg0 a5 a4 a3 a2 a1 a0 db13 db12 db11 db10 db9 db8 db7 C db0 mon_out 0 0 0 0 1 0 1 0 0 0 0 0 0 0 x vout0 0 0 0 0 1 0 1 0 0 0 0 0 0 1 x vout1 0 0 0 0 1 0 1 0 0 0 0 0 1 0 x vout2 0 0 0 0 1 0 1 0 0 0 0 0 1 1 x vout3 0 0 0 0 1 0 1 0 0 0 0 1 0 0 x vout4 0 0 0 0 1 0 1 0 0 0 0 1 0 1 x vout5 0 0 0 0 1 0 1 0 0 0 0 1 1 0 x vout6 0 0 0 0 1 0 1 0 0 0 0 1 1 1 x vout7 0 0 0 0 1 0 1 0 0 0 1 0 0 0 x vout8 0 0 0 0 1 0 1 0 0 0 1 0 0 1 x vout9 0 0 0 0 1 0 1 0 0 0 1 0 1 0 x vout10 0 0 0 0 1 0 1 0 0 0 1 0 1 1 x vout11 0 0 0 0 1 0 1 0 0 0 1 1 0 0 x vout12 0 0 0 0 1 0 1 0 0 0 1 1 0 1 x vout13 0 0 0 0 1 0 1 0 0 0 1 1 1 0 x vout14 0 0 0 0 1 0 1 0 0 0 1 1 1 1 x vout15 0 0 0 0 1 0 1 0 0 1 0 0 0 0 x vout16 0 0 0 0 1 0 1 0 0 1 0 0 0 1 x vout17 0 0 0 0 1 0 1 0 0 1 0 0 1 0 x vout18 0 0 0 0 1 0 1 0 0 1 0 0 1 1 x vout19 0 0 0 0 1 0 1 0 0 1 0 1 0 0 x vout20 0 0 0 0 1 0 1 0 0 1 0 1 0 1 x vout21 0 0 0 0 1 0 1 0 0 1 0 1 1 0 x vout22 0 0 0 0 1 0 1 0 0 1 0 1 1 1 x vout23 0 0 0 0 1 0 1 0 0 1 1 0 0 0 x vout24 0 0 0 0 1 0 1 0 0 1 1 0 0 1 x vout25 0 0 0 0 1 0 1 0 0 1 1 0 1 0 x vout26 0 0 0 0 1 0 1 0 0 1 1 0 1 1 x vout27 0 0 0 0 1 0 1 0 0 1 1 1 0 0 x vout28 0 0 0 0 1 0 1 0 0 1 1 1 0 1 x vout29 0 0 0 0 1 0 1 0 0 1 1 1 1 0 x vout30 0 0 0 0 1 0 1 0 0 1 1 1 1 1 x vout31 0 0 0 0 1 0 1 0 1 0 0 0 0 0 x vout32 0 0 0 0 1 0 1 0 1 0 0 0 0 1 x vout33 0 0 0 0 1 0 1 0 1 0 0 0 1 0 x vout34 0 0 0 0 1 0 1 0 1 0 0 0 1 1 x vout35 0 0 0 0 1 0 1 0 1 0 0 1 0 0 x vout36 0 0 0 0 1 0 1 0 1 0 1 1 0 1 x vout37 0 0 0 0 1 0 1 0 1 0 0 1 1 0 x vout38 0 0 0 0 1 0 1 0 1 0 0 1 1 1 x undefined ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 0 0 0 0 1 0 1 0 1 1 1 1 1 0 x undefined 0 0 0 0 1 0 1 0 1 1 1 1 1 1 x three - state figure 28 . channel monitor decoding 03731-028 db13 ?db8 channel address ad5380 channel monitor decoding 0 0 0 0 1 0 1 0 vout0 vout1 vout37 vout38 vout39/mon_out reg1 reg0 a5 a4 a3 a2 a1 a0 rev. d | page 25 of 40
ad5380 data sheet hardware functions reset function bringing the reset line low resets the contents of all internal registers to their power - on reset state. reset is a negative edge - sensitive input. the default corresponds to m at full scale and to c at zero scale . the contents of the dac registers are cleared, setting vout0 to vout39 to 0 v. the hardware reset activation time takes 270 s. the falling edge of reset initiates the reset process; busy goes low for the duration, returning high when reset is complete. while busy is low, all interfaces are dis abled and all ldac pulses are ignored. when busy returns high, the part resumes normal operation and the status of the reset pin is ignored until the next falling edge is detected. only perform a hardware reset when the ad5380 is not in power - down mode. asynchronous clear f unction bringing the c lr line low clears the contents of the dac registers to the data contained in the user configurable clr register and sets vout0 to vout9 accordingly. this func - tion can be used in system calibration to load zero scale and full scale t o all channels. the execution time for a clr is 35 s. busy and ldac functions busy is a digital cmos output that indicates the status of the ad5380 . the value of x2, the internal data loaded to the dac data register, is calculated each time the user writes new data to the corresponding x1, c, or m registers. during the calculation of x2, the busy output goes low. while busy is low, the user can continue writing new data to the x1, m, or c registers, but no dac output updates can take place. the dac outputs are updated by taking the ldac input low. if ldac goes low while busy is active, the ldac event is stored and the dac outputs update immediately after busy goes high. the user may hold the ldac i nput permanently low, in which case the dac outputs update immediately after busy goes high. busy also goes low during power - on reset and when a falling edge is also detected on the reset pin. during th is time, all interfaces are disabled and any events on ldac are ignored. the ad5380 contains an extra feature whereby a dac register is not up - dated unless its x2 register has be en written to since the last time ldac was brought low. normally, when ldac is brought low, the dac registers are filled with the contents of the x2 registers. however, the ad5380 will only update the dac register if the x2 data has changed, thereby removing unnecessary digital crosstalk. fifo operation in pa rallel mode the ad5380 contains a fifo to opti mize operation when operating in parallel interface mode. the fifo enable (level sensitive, active high) is used to enable the internal fifo. when connected to dvdd, the internal fifo is enabled allowing the user to write to the device at full speed. fifo is only available in parallel interface mode. the status of the fifo en pin is sam - pled on power - up, and after a clr or reset , to determine if the fifo is enabled. in either serial or i 2 c interface modes, fifo en should be tied low. up to 128 successive instructions can be written to the fifo at maximum speed in parallel mode. when the fifo is full, any further writes to the device are ignored. figure 29 shows a comparison between fifo mode and non - fifo mode in terms of channel update time. figure 29 also outlines digital loading time. figure 29 . channel update rate (fifo vs. non - fifo) power - on reset the ad5380 contains a power - on reset generator and state machine. the power - on reset resets all registers to a predefined state and configures the analog outputs as high impedance. the busy pin goes low during the power - on reset sequencing, preventing data writes to the device. power - down the ad5380 contains a global power - down feature that puts all channels into a low power mode and reduces the analog power consumption to 2 a max a nd digital power consumption to 20 a max. in power - down mode, the output amplifier can be configured as a high impedance output or provide a 100 k? load to ground. the contents of all internal registers are re - tained in power - down mode. when exiting power - down, the settling time of the amplifier will elapse before the outputs settle to their correct values. number of writes time ( s) 1 4 7 10 13 16 19 22 25 28 31 34 37 0 10 5 15 25 20 40 without fifo (channel update time) with fifo (channel update time) with fifo (digital loading time) 03731-029 rev. d | page 26 of 40
data sheet ad5380 ad5380 interfaces the ad5380 contains both parallel and serial interfaces. furthermore, the serial interface can be programmed to be either spi - , dsp - , microwire - , or i 2 c - compatible. the ser/ par pin selects parallel and serial interface modes. in serial mode, the spi /i 2 c pin is used to select dsp, spi, microwire, or i 2 c interface mode. the devices use an internal fifo memory to allow high speed successive writes in parallel inte rface mode. the user can con - tinue writing new data to the device while write instructions are being executed. the busy signal indicates the current status of the device, going low while instructions in the fifo are being executed. in par allel mode, up to 128 successive instructions can be written to the fifo at maximum speed. when the fifo is full, any further writes to the device are ignored. to minimize both the power consumption of the device and the on - chip digital noise, the active interface only powers up fully when the device is being written to, that is , on the falling edge of wr or the falling edge of syn c . dsp - , spi - , microwire - compatible serial interfaces the serial interface can be operated with a minimum of three wires in standalone mode or four wires in daisy - chain mode. daisy chaining allows many devices to be cascaded together to increase system channel count. the ser/ par pin must be tied high and the spi /i 2 c pin (pin 97) should be tied low to enable the dsp - /spi - /m icrowire - compatible serial interface. in serial interface mode, the user does not need to drive t he parallel input data pins. the serial interfaces control pins are sync , din, sclk standard 3 - wire interface pins. dcen selects standalone mode or daisy - chain mode. sdo data out pin for daisy - chain mode. figure 3 and figure 5 show timing diagrams for a serial write to the ad5380 in standalone and daisy - chain modes. the 24 - bit data - word format for the serial interface is shown in table 17. a /b . when toggle mode is enabled, this pin selects whether the data write is to the a or b register. with toggle disabled, this bit should be set to zero to select the a data register. r/ w is the read or write control bit. a5 to a0 are used to address the input channels. reg1 and reg0 select the register to which data is written, as shown in table 9 . db13 to db0 contain the input data - word. x is a dont care condition. standalone mode by connecting the dcen (daisy - chain enable) pin low, stand - alone mode is enabled. the serial interface works with both a continuous and a noncontinuous serial clock. the first falling edge of sync starts the write cycle and resets a counter that counts the number of serial clocks to ensure that the correct number of bits are shifted into the serial shift register. any further edges on s ync , except for a falling edge , are ignored until 24 bits are clocked in to the register . once 24 bits have been shifted in, the sclk is ignored. in order for another serial transfer to take place, the counter must be reset by the falling edge of sync . table 17 . 40- channel, 14 - bit dac serial input register configuration msb lsb a /b r/ w a5 a4 a3 a2 a1 a0 reg1 reg0 db13 db12 db11 db10 db9 db8 db7 db6 db5 db4 db3 db2 db1 db0 rev. d | page 27 of 40
ad5380 data sheet daisy - chain mode for systems that contain several devices, the sdo pin may be used to daisy - chain several devices together. this daisy - chain mode can be useful in system diagnostics and in reducing the number of serial interface lines. by connecting the dcen (daisy - chain enable) pin high, daisy - chain mode is enabled. the first falling edge of sync starts the write cycle. the sclk is conti nuously applied to the input shift register when sync is low. if more than 24 clock pulses are applied, the data ripples out of th e shift register and appears on the sdo line. this data is clocked out on the rising edge of sclk and is val id on the falling edge. by connecting the sdo of the first device to the din input on the next device in the chain, a multidevice interface is constructed. twenty - four clock pulses are required for each device in the system. therefore, the total number of clock cycles must equal 24n, where n is the total number of ad538x devices in the chain. when the serial transfer to all devices is complete, sync is taken high. this latches the input data in each device in the daisy - chain and prevents a ny further data from being clocked into the input shift register. if the sync is taken high before 24 clocks are clocked into the part, this is considered a bad frame and the data is discarded. the serial clock may be either a continuous or a gated clock. a continuous sclk source can only be used if it can be arranged that sync is held low for the correct number of clock cycles. in gated clock mode, a burst clock containing the exact number of clock cycles must be used an d sync must be taken high after the final clock to latch the data. readback mode readback mode is invoked by setting the r/ w bit = 1 in the serial input register write. with r/ w = 1, bits a5 to a0, in association with bits reg1 and reg0, select the register to be read. the remaining data bits in the write sequence are dont cares. during the next spi write, the data appearing on the sdo output will contain the d ata from the previously addressed register. for a read of a single register, the nop command can be used in clocking out the data from the selected register on sdo. figure 30 shows the readback sequence. for example, to read back the m register of channel 0 on the ad5380 , the following sequence should be implemented. first, write 0x404xxx to the ad5380 input register. this configures the ad5380 for read mode with the m register of channel 0 selected. note that d ata b its db13 to db 0 are dont cares. follow this with a second write, a nop condition, 0x000000. during this write, the data from the m register is clocked out on the sdo line, that is , data clocked out will contain the data from the m register in bits db13 to db0, and the top 10 bits contain the address infor - mation as previously written. in readback mode, the sync signal must frame the data. data is clocked out on the rising edge of sclk and is valid on the falling edge of the sclk signal. if the sclk idl es high between the write and read operations of a readback operation, the first bit of data is clocked out on the falling edge of sync . figure 30 . serial readback operation 03731-030 24 48 sclk sync din sdo undefined selected register data clocked out nop condition input word specifies register to be read db23 db0 db0 db23 db23 db0 db0 db23 rev. d | page 28 of 40
data sheet ad5380 i 2 c serial interface the ad5380 features an i 2 c - compatible 2 - wire interface consisting of a serial data line (sda) and a serial clock line (scl). sda and scl facilitate communication between the ad5380 and the master at rates up to 400 khz. figure 6 shows the 2 - wire interface timing diagrams that incorporate three different modes of operation. in selecting the i 2 c operating mode, first configu re serial operating mode (ser/ par = 1) and then select i 2 c mode by configuring the spi /i 2 c pin to a logic 1. the device is connected to the i 2 c bus as a slave device ( that is , no clock is generated by the ad5380 ). the ad5380 has a 7 - bit slave address 1010 1(ad1)(ad0). the 5 msb s are hard - coded, and the 2 lsbs are determined by the state of the ad1 and ad0 pins. the facility to hardware - configure ad1 and ad0 allows four of these devices to be configured on the bus. i 2 c data transfer one data bit is transferred during each scl clock cycle. the data on sda must remain stable during the high period of the s cl clock pulse. changes in sda while scl is high are control signals that configure start and stop conditions. both sda and scl are pulled high by the external pull - up resistors when the i 2 c bus is not busy. start and stop conditions a master device initia tes communication by issuing a start condition. a start condition is a high - to - low transition on sda with scl high. a stop condition is a low - to - high transition on sda while scl is high. a start condition from the master signals the beginning of a transmis sion to the ad5380 . the stop condition frees the bus. if a repeated start condition (sr) is generated instead of a stop condition, the bus remains active. repeated start conditions a repeated star t (sr) condition may indicate a change of data direction on the bus. sr may be used when the bus master is writing to several i 2 c devices and wants to maintain control of the bus. acknowledge bit (ack) the acknowledge bit (ack) is the ninth bit attached to any 8 - bit data - word. ack is always generated by the receiving device. the ad5380 devices generate an ack when receiving an address or data by pulling sda low during the ninth clock period. monit oring ack allows for detection of unsuccessful data transfers. an unsuccessful data transfer occurs if a receiv - ing device is busy or if a system fault has occurred. in the event of an unsuccessful data transfer, the bus master should reattempt communicati on. ad5380 slave addresses a bus master initiates communication with a slave device by issuing a start condition followed by the 7 - bit slave address. when idle, the ad5380 waits for a start condition followed by its slave address. the lsb of the address word is the read/ write (r/ w ) bit. the ad5380 is a receive only device; when communicating with the ad5380 , r/ w = 0. after receiving the proper address 1010 1(ad1)(ad0), the ad5 380 issues an ack by pulling sda low for one clock cycle. the ad5380 has four different user programmable addresses determined by the ad1 and ad0 bits. write operation there are three specific mod es in which data can be written to the ad5380 dac. 4 - byte mode when writing to the ad5380 dacs, the user must begin with an address byte (r/ w = 0), after which the dac acknowledges that it is prepared to receive data by pulling sda low. the address byte is followed by the pointer byte; this addresses the specific channel in t he dac to be addressed and is also acknowledged by the dac. two bytes of data are then written to the dac, as shown in figure 31 . a stop condition follows. this allows the user to update a single channel within the ad5380 at any time and requires four bytes of data to be transferred from the master. 3 - byte mode in 3 - byte mode, the user can update more than one channel in a write sequence without having to write the device address byte each time. the device address byte is only required once; sub - sequent channel updates require the pointer byte and the data bytes. in 3 - byte mode, the user begins with an address byte (r/ w = 0) , after which the dac will acknowledge that it is prepared to receive data by pulling sda low. the address byte is followed by the pointer byte. this addresses the specific chan - nel in the dac to be addressed and is also acknowledged by the dac. this is then followed by the two data bytes. reg1 and reg0 determine the register to be updated. if a stop condition does not follow the data bytes, another channel can be updated by sending a new pointer byte followed by the data bytes. this mode only requires three bytes to be sent addressed, and reduces the software overhead in updating the ad5380 channels. a stop condition at any time exits this mode. figure 32 shows a typical configuration. rev. d | page 29 of 40
ad5380 data sheet figure 31 . 4 - byte ad5380 , i 2 c write operation figure 32 . 3 - byte ad5380 , i 2 c write operation 1 0 1 0 1 ad1 ad0 r/w 0 0 a5 a4 a3 a2 a1 a0 scl sda scl sda st art cond by master ack b y ad538x ack b y ad538x address byte most significant byte least significant byte pointer byte msb ack b y ad538x ack b y ad538x st op cond by master reg1 reg0 msb lsb msb lsb 03731-031 03731-032 scl sda sda scl sda scl sda scl st art cond by master ack b y ad538x msb address byte pointer byte for channe l "n" most significant d at a byte pointer byte for channe l "next channel" least significant d at a byte most significant d at a byte least significant d at a byte ack b y ad538x ack b y ad538x dat a for channe l "n" dat a for channe l "next channel" ack b y ad538x 1 0 0 a5 a4 a3 a2 a1 a0 0 1 0 0 0 a5 a4 a3 a2 a1 a0 1 ad1 ad0 r/w reg1 reg0 msb lsb msb lsb msb ack b y ad538x ack b y ad538x ack b y ad538x st op cond by master reg1 reg0 msb lsb msb lsb rev. d | page 30 of 40
data sheet ad5380 2 - byte mode following initialization of 2 - byte mode, the user can update channels sequentially. the device address byte is only required once and the pointer address pointer is configured for auto - increment or b urst mode. the user must begin with an address byte (r/ w = 0), after which the dac will acknowledge that it is prepared to receive data by pulling sda low. the address byte is followed by a specific pointer byte (0xff) that initiates the burst mode of operation. the address pointer initializes to channel 0, the data foll owing the pointer is loaded to c hannel 0, and the address pointer automatically increments to the next address. the reg0 and reg1 bits in the data byte determine which regi ster will be updated. in this mode, following the initializa - tion, only the two data bytes are required to update a channel. the channel address automatically increments from address 0 to channel 39 and then returns to the normal 3 - byte mode of operation. this mode allows transmission of data to all channels in one block and reduces the software overhead in configuring all channels. a stop condition at any time exits this mode. toggle mode is not supported in 2 - byte mode. figure 33 shows a typical configuration. parallel interface the ser/ par pin must be tied low to enable the parallel inter - face and disable the serial interfaces. figure 7 shows the timing diagram for a parallel write. the parallel interface is controlled by the following pins: cs pin active low device select pin. wr pin on th e rising edge of wr , with cs low, the addresses on pin a5 to pin a0 are latched; data present on the data bus is loaded into the selected input registers. reg0, reg1 pins the reg0 and reg1 pins determine the destination register of the data being written to the ad5380 . see table 9 . pins a5 to a0 each of the 40 dac channels can be individually addressed. pins db13 to db0 the ad5380 accepts a straight 14 - bit parallel word on db13 to db0, where db13 is the msb and db0 is the lsb. figure 33 . 2 - byte, 1 2 c write operation 1 0 1 0 1 ad1 ad0 r/w a7 = 1 a6 = 1 a5 = 1 a4 = 1 a3 = 1 a2 = 1 a1 = 1 a0 = 1 s t art cond b y master address byte pointer byte most significant d at a byte channe l 0 d at a least significant d at a byte ack b y converter msb ack b y converter ack b y ad538x ack b y ad538x most significant d at a byte channe l 1 d at a least significant d at a byte ack b y converter ack b y converter most significant d at a byte channe l n d at a followed b y s t o p least significant d at a byte ack b y converter ack b y converter s t o p cond b y master reg1 reg0 msb lsb msb lsb reg1 reg0 msb lsb msb lsb reg1 reg0 msb lsb msb lsb sc l sd a sc l sd a sc l sd a sc l sd a 03731-033 rev. d | page 31 of 40
ad5380 data sheet microprocessor inter facing parallel interface the ad5380 can be interfaced to a variety of 16 - bit microcon - trollers or dsp processors. figure 35 shows the ad5380 family interfaced to a generic 16 - bit microcontroller/dsp processor. the lower address lines from the processor are connected to a0 to a5 on the ad5380 . the upper address lines are de coded to provide a cs , ldac s ignal for the ad5380 . the fast interface timing of the ad5380 allows direct interface to a wide variety of microcontrollers and dsps, as shown in figure 35. ad5380 to mc68hc11 the serial peripheral interface (spi) on the mc68hc11 is configured for master mode (mstr = 1), clock polarity bit (cpol) = 0, and the clock phase bit (cpha) = 1. the spi is configured by writing to the spi control register (spcr) se e the 68hc11 user manual . sck of the 68hc11 drives the sclk of the ad5380 , the mosi output drives the serial data line (din) of the ad5380 , and the miso input is driven from sdo. the sync signal is derived from a port line (pc7). when data is being transmitted to the ad5380 , the sync line is taken low (pc7). data appearing on the mosi output is valid on the falling edge of sck. serial data from the 68hc11 is transmitted in 8 - bit bytes with only eight falling clock edges occurring in the transmit cycle. figure 34 . ad5380 - to - mc68hc11 interface figure 35 . ad5380 - to - parallel interface 03731-034 mc68hc11 ad5380 miso mosi sck pc7 sdo reset ser/par din sclk sync spi/i 2 c dvdd 03731-035 controller/ dsp processor 1 ad5380 address decode upper bits of address bus data bus a5 d15 d0 a4 a3 a2 a1 a0 r/w a5 a4 a3 a2 a1 a0 wr reg1 reg0 d13 d0 cs ldac 1 additional pins omitted for clarity. rev. d | page 32 of 40
data sheet ad5380 ad5380 to pic16c6x/7x the pic16c6x/7x synchronous serial port (ssp) is configured as an spi master with the clock polarity bit = 0. this is done by writing to the synchronous serial port control register (sspcon). see the pic16/17 microcontroller user manual . in this example, i/o, port ra1, is being used to pulse sync and enable the serial port of the ad5380 . this microcontroller transfers only eight bits of data during each serial transfer operation; therefore, three consecutive read/write operations may be needed depending on the mode. figure 36 shows the connection diagram. figure 36 . ad5380 - to - pic16c6x/7x interface ad5380 to 8051 the ad5380 requires a clock synchronized to the serial data. t herefore , t he 8051 serial interface must be operated in mode 0. in this mode, s erial data enters and exits through rxd, and a shift clock is output on txd. figure 37 shows how the 8051 is connected to the ad5380 . because the ad5380 shifts data out on the rising edge of the shift clock and latches data in on the falling edge, the shift clock must be inverted. the ad5380 requires its data to be msb first. since the 8051 outputs the lsb first, the transmit routine must take this into account. figure 37 . ad5380 - to - 8051 interface ad5380 to adsp - bf527 figure 38 shows a serial interface between the ad5380 and the adsp - bf527 . the adsp - bf527 should be set up to operate in sport transmit alternate framing mode. the adsp - bf527 sport is programmed through the sport control register and should be configured as follows: internal clock operation, active low framing, and 16 - bit word length. transmission is initiated by writing a word to t he tx register after the sport has been enabled. figure 38 . ad5380 - to - adsp - bf527 interface 03731-036 pic16c6x/7x ad5380 sdi/rc4 sdo/rc5 sck/rc3 ra1 sdo reset ser/par din sclk sync spi/i 2 c dvdd 03731-037 8xc51 ad5380 rxd txd p1.1 sdo reset ser/par din sclk sync spi/i 2 c dvdd adsp-bf527 sync sport_tfs sport_rfs sclk sport_tsck sport_rsck din sport_dt0 sdo sport_dr0 ad5380 03731-038 * additiona l pins omitted for clarit y rev. d | page 33 of 40
ad5380 data sheet application s information power supply decoupl ing in any circuit where accuracy is important, careful considera - tion of the power supply and ground return layout helps to ensure the rated performance. the printed circuit board on which the ad5380 is mounted should be designed so that the analog and digital sections are separated and confined to certain areas of the board. if the ad5380 is in a system where multiple devices require an agnd - to - dgnd connection, the connection should be made at one point only, a star ground point established as close to the device as possible. for supplies with multiple pins (avdd, dvdd), these pins should be tied together. the ad5380 should have ample supply bypassing of 10 f in parallel with 0.1 f on each supply, located as close to the package as possible and ideally right up against the device. the 10 f capacitors are the tantalum bead type. the 0.1 f capacitor should have low effective series resis - tance (esr) and effective series inductance (esi), like the common ceramic types that provide a low impedance path to ground at high frequencies, to handle transient currents due to internal logic sw itching. the power supply lines of the ad5380 should use as large a trace as possible to provide low impedance paths and reduce the effects of glitches on the power supply line. fast switching sig nals such as clocks should be shielded with digital ground to avoid radiating noise to other parts of the board, and should never be run near the reference inputs. a ground line routed between the din and sclk lines will help reduce crosstalk between them (this is not required on a multilayer board because there will be a separate ground plane, but separating the lines will help). it is essential to minimize noise on the refout/refin line. avoid crossover of digital and analog signals. traces on opposite si des of the board sho uld run at right angles to each other. this reduces the effects of feedthrough through the board. a micro - strip technique is the best, but is not always possible with a double - sided board. in this tech nique, the component side of the b oard is dedicated to the ground plane while signal traces are placed on the solder side. power supply sequenc ing for proper operation of the ad5380 , apply dv dd first and then av dd simultaneously o r within 10 ms of dv dd . this sequence ensures that the power on reset circuitry sets the registers to their default values and keeps the analog outputs at 0 v until a valid write operation takes place. when av dd cannot be applied within 10 ms of dv dd, issue a hardware reset. this triggers the power on reset circuitry and loads the default register values. for cases where the initial power supply has the same or a lower voltage than the second power supply , a schottk y diode can be used to temporarily su pply power until the second power supply turns on. ta bl e 18 lists the power supply sequences and the recommended diode connection s. alternatively, a lo ad switch such as the adp196 can be used to delay the first power supply until the second power supply turns on. figure 41 shows a typical configurati on using the adp196 . in this case , the avdd is applied first. this voltage does not appear at the avdd pin of the ad5380 until the dvdd is applied and brings the en pin high. the result is that th e avdd and dvdd are both applied to the ad5380 at the same time. table 18 . power supply sequencing first power supply second power supply recommended operation av dd = 3 v dv dd 3 v see figure 39 dv dd = 3 v av dd 3 v see figure 40 av dd = dv dd dv dd = av dd see figure 39 ; assumes separ ate analog and digital supplies dv dd = av dd av dd = dv dd see figure 40 ; assumes separate analog and digital supplies av dd = 5 v dv dd = 3 v see figure 41 dv dd = 5 v av dd = 3 v hardware reset or see figure 42 figure 39 . avdd first f ollowed by dvdd figure 40 . dvdd f irst f ollowed by avdd 03731-130 gnd dac gnd dgnd agnd a vdd = 3v dvdd 3v ad5380 signal a vdd dvdd sd103c or equi v alent 03731-132 gnd dac gnd dgnd agnd a vdd 3v dvdd = 3v ad5380 signal a vdd dvdd sd103c or equi v alent rev. d | page 34 of 40
data sheet ad5380 rev. d | page 35 of 40 figure 41. avdd power supply controlled by a load switch figure 42. dvdd power supply controlled by a load switch typical configuration circuit figure 43 shows a typical configuration for the ad5380-5 when configured for use with an external reference. in the circuit shown, all agnd, signal_gnd, and dac_gnd pins are tied together to a common agnd. agnd and dgnd are connected together at the ad5380 device. on power-up, the ad5380 defaults to external reference operation. all avdd lines are connected together and driven from the same 5 v source. it is recommended to decouple close to the device with a 0.1 f ceramic and a 10 f tantalum capacitor. in this application, the reference for the ad5380-5 is provided externally from either an adr421 or adr431 2.5 v reference. suitable external references for the ad5380-3 include the adr3412 1.2 v reference. the reference should be decoupled at the refout/refin pin of the device with a 0.1 f capacitor. figure 43. typical configurat ion with external reference figure 44 shows a typical configuration when using the internal reference. on power-up, the ad5380 defaults to an external reference; therefore, the internal reference needs to be config- ured and turned on via a write to the ad5380 control register. control register bit cr12 allows the user to choose the reference value; bit cr 10 is used to select the internal reference. it is recommended to use the 2.5 v reference when avdd = 5 v, and the 1.25 v reference when avdd = 3 v. figure 44. typical configuration with internal reference digital connections have been omitted for clarity. the ad5380 contains an internal power-on reset circuit with a 10 ms brown- out time. if the power supply ramp rate exceeds 10 ms, the user should reset the ad5380 as part of the initialization process to ensure the calibration data gets loaded correctly into the device. vin1 adp196 a d5380 en agnd avdd dvdd vin2 vout1 vout2 agnd dgnd avdd dvdd 03731-134 vin1 adp196 a d5380 en agnd dvdd avdd vin2 vout1 vout2 agnd dgnd dvdd avdd 03731-131 03731-039 adr431/ adr421 ad5380-5 avdd dvdd signal_gnd dac_gnd dgnd vout39 vout0 agnd refout/refin refgnd 0.1 ? f 10 ? f 0.1 ? f 0.1 ? f avdd dvdd 03731-040 ad5380 avdd dvdd signal_gnd dac_gnd dgnd vout39 vout0 agnd refout/refin refgnd 0.1 ? f 10 ? f 0.1 ? f 0.1 ? f a vdd dvdd
ad5380 data sheet rev. d | page 36 of 40 ad5380 monitor function the ad5380 contains a channel monitor function that consists of a multiplexer addressed via the interface, allowing any chan- nel output to be routed to this pin for monitoring using an external adc. in channel monitor mode, vout39 becomes the mon_out pin, to which all monitored signals are routed. the channel monitor function must be enabled in the control register before any channels are routed to mon_out. table 16 contains the decoding information required to route any channel to mon_out. selecting channel address 63 three-states mon_out. figure 45 shows a typical monitoring circuit implemented using a 12-bit sar adc in a 6-lead sot-23 package. the controller output port selects the channel to be monitored, and the input port reads the converted data from the adc. figure 45. typical channel monitoring circuit toggle mode function the toggle mode function allows an output signal to be gener- ated using the ldac control signal that switches between two dac data registers. this function is configured using the sfr control register as follows. a write with reg1 = reg0 = 0 and a5 to a0 = 001100 specifies a control register write. the toggle mode function is enabled in groups of eight channels using bits cr6 to cr2 in the control register. see the ad5380 control register description. figure 46 shows a block diagram of toggle mode implementation. each of the 40 dac channels on the ad5380 contain an a and b data register. note that the b registers can only be loaded when toggle mode is enabled. the sequence of events when configuring the ad5380 for toggle mode is 1. enable toggle mode for the required channels via the control register. 2. load data to a registers. 3. load data to b registers. 4. apply ldac . the ldac is used to switch between the a and b registers in determining the analog output. the first ldac configures the output to reflect the data in the a registers. this mode offers significant advantages if the user wants to generate a square wave at the output of all 40 channels, as might be required to drive a liquid crystal based variable optical attenuator. in this case, the user writes to the control register and enables the toggle function by setting cr6 to cr2 = 1, thus enabling the five groups of eight for toggle mode operation. the user must then load data to all 40 a and b registers. toggling ldac will set the output values to reflect the data in the a and b registers. the frequency of the ldac will determine the frequency of the square wave output. toggle mode is disabled via the control register. the first ldac following the disabling of the toggle mode will update the outputs with the data contained in the a registers. figure 46. toggle mode function ad7476 gnd sdata cs sclk vdd vin vout39/mon_out agnd din sync sclk dac_gnd signal_gnd vout0 v out38 avdd ad5380 output port input port controller 03731-041 14-bit dac dac register input data input register data register b data register a a/b vout ldac control input 03731-042
data sheet ad5380 thermal monitor func tion the ad5380 contains a temperature shutdown function to protect the chip in case multiple outputs are shorted. the short - circuit current of each output amplifier is typically 40 ma. operating the ad5380 at 5 v produces a power dissipation of 200 mw per shorted amplifier. with five channels shorted, this gives an extra watt of power dissipation. for the 100 - l e a d l q f p, the ja is typically 44c/w. the thermal monitor is enabled by the user via cr8 in the control register. the output amplifiers on the ad5380 are automatically powered down if the die temperature exceeds approximately 130c. a fter a thermal shutdown has occurred, the user can re - enable the part by executing a soft power - up if the temperature has dropped below 130c or by turning off the thermal monitor function via the control register. ad5380 in a mems based opti cal switch in their feed - forward control paths, mems based optical switches require high resolution dacs that offer high channel density with 14 - bit monotonic behavior. the 40 - channel, 14 - bit ad5380 dac satisfies these requirements. in the circuit in figure 47 , the 0 v to 5 v outputs of the ad5380 are amplified to achieve an output range of 0 v to 200 v, which is used to control actuators that determine the position of mems mirrors in an optical switch. the exact position of each mirro r is measured using sensors. the sensor outputs are multiplexed into a high resolution adc in determining the mirror position. the control loop is closed and driven by an adsp - 21065l , a 32- bi t sharc? dsp with an spi - compatible sport interface. the adsp - 21065l writes data to the dac, controls the multiplexer, and reads data from the adc via the serial interface. figure 47 . ad5380 in a mems based optical switch actuators for mems mirror array sensor and multiplexer 8-channel adc (ad7856) or single channel adc (ad7671) ad5380 14-bit dac 14-bit dac refout/refin avdd vout1 vout39 g = 50 g = 50 output range 0v to 200v adsp-21065l 0.01 f 03731-043 +5v rev. d | page 37 of 40
ad5380 data sheet optical attenuators based on its high channel count, high resolution, monotonic behavior, and high level of integration, the ad5380 is ideally targeted at optical attenuation applications used in dynamic gain equaliz ers, variable optical attenuators (voa), and optical add - drop multiplexers (oadm). in these applications, each wavelength is individually extracted using an arrayed wave guide; its power is monitored using a photodiode, transim - pedance amplifier and adc in a closed - loop control system. the ad5380 controls the optical attenuator for each wavelength, ensuring that the power is equalized in all wavelengths before being multiplexed onto the fiber. thi s prevents information loss and saturation from occurring at amplification stages further along the fiber. figure 48 . oadm using the ad5380 as part of an optical attenuator attenuator attenuator attenuator attenuator awg awg fibre fibre dwdm out optical switch 11 12 1n ? 1 1n dwdm in ad5380, 40-channel, 14-bit dac n:1 multiplexer 16-bit adc controller tia/log amp (ad8304/ad8305) adg731 (40:1 mux) ad7671 (0v to 5v, 1msps) photodiodes add ports drop ports 03731-044 rev. d | page 38 of 40
data sheet ad5380 utilizing the ad5380 fifo the ad5380 fifo mode optimizes total system update rates in applications where a large number of channels need to be updated. fifo mode is only available when parallel interface mode is selected. the fifo en pin is used to enable the fifo. the status of fifo en is s ampled during the initialization sequence. therefore, the fifo status can only be changed by resetting the device. in a telescope that provides for the cancella - tion of atmospheric distortion, for example, a large number of channels need to be updated in a short period of time. in such systems, as many as 400 channels need to be updated within 40 s. four - hundred channels requires the use of 10 ad5380 s. with fifo mode enabled, the data write cycle time is 40 ns; therefore, each group consisting of 40 channels can be fully loaded in 1.6 s. in fifo mode, a complete group of 40 channels will update in 14.4 s. the time taken to update all 400 channels is 14.4 s + 9 1.6 s = 28.8 s. figure 49 shows the fifo operation scheme. figure 49 . using fifo mode 400 channels updated in under 30 s group a chnls 0?39 group b chnls 40?79 group c chnls 80?119 group d chnls 120?159 group e chnls 160?199 group f chnls 200 ?239 group g chnls 240?279 group h chnls 280?319 group i chnls 320?359 group j chnls 360?399 time to update 400 channels = 28.8 s 1.6s 14.4s 14.4s 1.6s fifo data load group a fifo data load group b output update time for group a 1.6s 14.4s fifo data load group j output update time for group j output update time for group b 03731-045 rev. d | page 39 of 40
ad5380 data sheet outline dimensions figure 50 . 100 - lead low profile quad flat package [lqfp] (st - 100 - 1) dimensions shown in millimeters ordering guide model 1 resolution temperature range avdd range output channels linearity error (lsb) package description package option ad5380bst z -3 14 bits C 40c to +85c 2.7 v to 3.6 v 40 4 100 - lead lqfp st - 100 -1 ad5380bst z -5 14 bits C 40c to +85c 4.5 v to 5.5 v 40 4 100 - lead lqfp st - 100 -1 eval - ad5380eb z evaluation kit 1 z = rohs - compliant part. i 2 c refers to a communications protocol originally developed by philips semiconductors (now nxp semiconductors). compliant t o jedec s t andards ms-026-bed t o p view (pins down) 1 25 26 51 50 75 76 100 0.50 bsc lead pitch 0.27 0.22 0.17 1.60 max 0.75 0.60 0.45 view a pin 1 1.45 1.40 1.35 0.15 0.05 0.20 0.09 0.08 coplanarit y view a ro ta ted 90 ccw se a ting plane 7 3.5 0 14.20 14.00 sq 13.80 16.20 16.00 sq 15.80 051706- a ? 2004 C 2014 analog devices, inc. all rights reserved. trademarks and registered trademarks are the property of their respective owners. d03731 - 0 - 5/14(d) rev. d | page 40 of 40

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