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general description this core is a cmos hexa-channel 10bit 40msps d/a converter for general & video applications. the dac1243x-al core is implemented in the samsung 0.25um 2.5v cmos process. digital inputs are coded as straight binary. each dac channel includes independent power down control and the ability to sense output load. an external(optional) or internal 0.7v reference voltage(vbias) and a single external resister define the full-scale output current together. it uses the two architecture of current-segment and binerary-weighted. functional block diagram features maximum conversion rate is 40msps +2.5v cmos monolithic construction 0.75lsb differential linearity (typical) 1.0lsb integral linearity (typical) external or internal voltage reference (including band gap reference block) hexa channel dac 10-bit parallel straight binary digital input per channel dac auto-load detection circuitry temperature : 0 ~ 70 c each channel power_down typical application high definition television(hdtv) high resolution color graphics harddiskdriver(hdd) cae/cad/cam image processing instrumentation ver 1.3 (aug. 2000) this datasheet is a preliminary version. no responsibility is assumed by sec for its use nor for any infringements of patents or other rights of third parties that may result from its use. the content of this datasheet is subject to change without any notice. 10bit 40msps hexa-channel dac dac1243x_al samsung electronics co. ltd 1/15 digital decode binary weighted lsbs segmented msbs d1[9:0] pdac1 digital decode binary weighted lsbs segmented msbs d2[9:0] pdac2 digital decode binary weighted lsbs segmented msbs d3[9:0] pdac3 digital decode binary weighted lsbs segmented msbs d6[9:0] pdac6 digital decode binary weighted lsbs segmented msbs d5[9:0] pdac5 digital decode binary weighted lsbs segmented msbs d4[9:0] pdac4 auto-load detect bias_gen dtout pre sel<2:0> allpd iref vbias ccomp io1 io2 io3 io4 io5 io6 vdd25aa1,vdd25ad1 vss25aa1,vss25ad1 vabb clk
sec asic dac1243x-al 10bit 30msps hexa channel dac analog name i/o type i/o pad pin description pdac[5:0] di piar50_abb individual dac power down control. when activated(high), the corresponding dacisdisabled. clk di picc_abb dac master clock. input data is sampled with the rising edge of clk . pre di piar50_abb control strobe for the dac auto-load detection comparator. when pre transitions high-to-low, the auto-load detect circuit evaluates its selected input. appropriate settling time must be allowed before the comparator output (dtout) is used. when not used, pre should be left high. d1[9:0] d2[9:0] d3[9:0] d4[9:0] d5[9:0] d6[9:0] di picc_abb 10-bit straight binary digital input for each dac channel. allpd di piar50_abb power down control for bandgap and all six dacs. a high level disables all six dacs plus the bandgap reference regardless of the states of pdac0-5 dtout do pot8_abb comparator output for detection of resistive load at dac output. a low at the detect output indicates that the output voltage of the selected channel is above 0.53v and therefore that no load is attached. ccomp ab poa_bb internal dac compensation node. connect external 0.1uf cap to vdd25aa1 . irset ab poa_bb external resistor from this node to vss25aa1 defines the full scale output current for the dacs. vbias ab poa_bb external reference voltage output. pin configuration i/o type abbr. ai : analog input di : digital input ao : analog output do : analog output ab : analog bidirectional db : digital bidirectional ap : analog power ag : analog ground dp : digital power dg : digital ground 2/15
sec asic dac1243x-al 10bit 30msps hexa channel dac analog name i/o type i/o pad pin description vdd25aa1 ap vdd2t_bb analog power (needs 3 pads) vss25aa1 ag vss2t_abb analog ground (needs 3 pads) vdd25ad1 dp vdd2t_abb digital power vss25ad1 dg vss2t_abb digital ground vabb ag vbb_abb substrate bias(the same with ground level) io1 ao poa_bb 1st analog current output io2 ao poa_bb 2nd analog current output io3 ao poa_bb 3rd analog current output io4 ao poa_bb 4th analog current output io5 ao poa_bb 5th analog current output io6 ao poa_bb 6th analog current output i/o type abbr. ai : analog input di : digital input ao : analog output do : analog output ab : analog bidirectional db : digital bidirectional ap : analog power ag : analog ground dp : digital power dg : digital ground 3/15
sec asic dac1243x-al 10bit 30msps hexa channel dac analog core configuration vdd25aa1 vdd25ad1 vss25ad1 vss25aa1 vbba io2 dac1243x-al d1[10:0] d2[10:0] allpd clk io1 ccomp irset vbias d3[10:0] d4[10:0] d5[10:0] d6[10:0] pdac[6:1] dtct_out pre sel[2:0] io3 io5 io6 io4 dtout 4/15 pdac[5:0]
sec asic dac1243x-al 10bit 30msps hexa channel dac analog characteristic symbol value unit supply voltage vdd25aa1 - vss25aa1 vdd25ad1 - vss25ad1 2.5 v voltage on any digital pin clk vss25ad1-0.25 to vdd25ad1+0.25 v storage temperature range t stg -45 ~ 125 oc notes 1. absolute maximum rating specifies the values beyond which the device may be damaged permanently. exposure to absolute maximum rating conditions for extended periods may affect reliability. each condition value is applied with the other values kept within the following operating conditions and function operation under any of these conditions is not implied. 2. all voltages are measured with respect to gnd unless otherwise specified 3. applied voltage must be limited to specified range. characteristics symbol min typ max unit operating supply voltage vdd25ad1,vdd25aa1 2.25 2.5 2.75 v digital input voltage high v ih 1.75 2.5 - v digital input voltage low v il - 0.0 0.75 v operating temperature range topr 0 25 70 oc output load(effective) r l - 37.5 - ? reference load(effective) resistor rset - 658 - ? reference voltage v bia s - 0.7 - v data input setup time t s 4 - - ns data input hold time t h 1 - - ns clock cycle time t clk 25 - - ns clock pulse width high t pwh 12 - - ns clock pulse width low t pwl 12 - - ns zero_level voltage v oz -10 -5 +10 mv irset current i ref 0.9 1.06 1.1 ma notes 1. it is strongly rec ommended that all the s upply pins (vdd25aa1,vdd25ad2) be powered from the same source and all the ground pins(vss25aa1,vss25ad1,vabb) avoid power latch-up. absolute maximum ratings recommended operating conditions 5/15
sec asic dac1243x-al 10bit 30msps hexa channel dac analog dc electrical characteristics ac electrical characteristics note: the above parameters are not tested through the temperature range, but these are guaranted over the full temperature range. clock & data feedthrough is a function of the amount of overshoot and undershoot on the digital inputs. settling time does not include clock and data feedthrough . glitch impulse include clock and data feedthrough. notes 1. converter specifications (unless otherwise specified) : vdd25aa1=vdd25ad1=2.5v vss25aa1=vss25ad1=gnd, ta=25 c, rset=658 ? ,r load1 =r load2 =r load3 ==r load4 =r load5 =r load6 =37.5 ? c ccomp =0.1uf 2. tbd : to be determined characteristics symbol min typ max unit resolution - - - 10 bits full scale current per channel ifs - 34 - ma differential linearity error dle - 0.75 1.0 lsb integral linearity error ile - 1.0 2.0 lsb monotonicity - guaranteed - output compliance voc 0 - +1.3 v power dissipation pdiss - 600 700 mw characteristics symbol min typ max unit analog dac output capacitance c in - 20 - pf minimum delay from sel[2:0] transition to pre transition low t sell 100 - - ns minimum delay from pre transition low to valid dtout output t det_val 100 - - ns minimum pulse width low for pre t spwl 200 - - ns mismatching mm - 11 - lsb power supply rejection ratio(5.8khz) psrr 35 45 - db conversion rate f con - 30 40 mhz analog output delay td - 10 - ns analog output rise time tr - 5 - ns analog output fall time tf - 5 - ns analog output settling time tset - 60 - ns clock & data feedthrough fdthr 25 30 - db glitch impulse gl - 100 200 pv*sec pipeline delay top 0.5 0.7 1.0 clk supply current is 190 210 230 ma 6/15
sec asic dac1243x-al 10bit 30msps hexa channel dac analog this is hexa 10bit 40msps digital to analog data converter and uses current-segment architecture for 6bits of msb sides and binerary-weighted architecture for 6bits of lsb side. it contains of 1st latch block, decoder block,2nd latch block,opa block,cm(current mirror)block ,bgr(band gap reference) block, auto-load detect block and analog switch block, etc. this core uses reference current which decide the 1lsb current by dividing the reference current by 32times. so the reference current must be constant and it can be constant by using opa block with high dc gain. the most significant block of this core is analog switch block and it must maintain the uniformity at each switch, so layout designer must care of it. and more than 90% of supply current is dissipated at analog switch block. and it uses samsung standard cell as all digital cell of latch, decoder and buffer, etc. and to adjust full current output range, you must decide the rset value(connected to irset pin) and. its voltage output can be obtained by connecting rl1(connected to io1 pin) and rl2(connected to io2 pin) ,rl3(connected to io3 pin) and rl4(connected to io4 pin), rl5(connected to io5 pin and rl6(connected to io6 pin). its maximum output voltage limit is compliance vlotage. so you must decide the rl[6:1], vbias and rset carefully not to exceed the output voltage limit. it contains pdac[5:0] pins for power-save of each channel and allpd for power-down mode of all blocks. even though one or two out of 6 channels enter power-save mode, the reference block(opa block,cm block, bgr block) is still alive, but if allpd is activated(high), then all blocks of this core is disable regardless of pdac[5:0], so at this case supply current is almost just about the sum of leakage. you cant check the bgr's output voltage by checking the vbias pin. the user can detect the presence of an expected load on each dac output by configuring the dac digital inputs such that the detection comparator threshold(0.53v) is a useful threshold for presence of load resistance. set sel[3:0] to select the appropriate dac output. transition pre to low, wait for settling dtout value and return pre back to high. the irset pin creates a +0.7vdc reference that can be forced with an external reference voltage ap pin vbias. this voltage when combined with the external resistor attached to the irset pin sets the output current range for all six dacs. the following example shows how to create a 1vpk-pk output for a 100 ire ntsc signal. any other required variations can easily be calculated from the supplied equations. please remember that these are ideal equations, the mismatch tolerances from the data sheet should be taken into account for any calculations. the

diagram shows a typical relationship between dac input and voltage output. the

diagram shows the basic bias-generator and analog current switch. from this diagram the number of dac codes for a 1v delta output is : c100 = 808 - 10 = 798 1v 808 10 dac code input an example 10-bit dac relationship input code verse output level

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sec asic dac1243x-al 10bit 30msps hexa channel dac analog

if a standard doubly terminated 75 ohm line is assumed : v 100 1 i 100 = -------- = --------- = 26.666ma r load 37.5 the relationship between the ir reference current and dac output current is shown below. ir = 32 lsb from the previous equation we have: irset 0.7v r set = --------- = ------------- = 654 ? i r 1.069ma summation of all equations gives : irset * c 100 *r load r set = ------------------------------ 32*v 100 for most video applications an external resistor of 649 ?(+/? 1%) would be selected when driving doubly terminated loads (37.5 ?), and an external resistor of 1.3k ?(+/?1%) would be selected when driving loads of 75 ? ,in order to have 798 dac codes correspond to a 1v delta output voltage swing. then the dac output levels and the associated codes are as shown below. table 1:summary of dac voltage and codes signal level cvbs/luma dac code ire value dac voltage max output 1023 137.2 1.282v 100% white 810 100 1.015v black 282 7.37 353mv sync 12 -40 15mv white - black 570 100 714mv delta white - wync 798 140 1v delta color burst 228 40 285mv delta dac voltages assume the standard 140 ire = 1v. numbers shown are for ntsc type video with a pedestal. reference generator ccomp iref current for 1 lsb external resistor i r 8/15
sec asic dac1243x-al 10bit 30msps hexa channel dac analog timing diagram notes: the behavioral modeling is provided by verilog output delay(td) measured from the 50% point of the rising edge of clk to the full scale trasition settling time(tset) measured from the 50% point of full scale transition to the output remaining within 1lsb iteration. output rising(tr)/falling(tf) time measured between the 10% and 90% points of full scale transition. any power_down doesn't need clock signal. pd1(pd2,pd3, ,pd6) makes the 1st(2nd,3rd, ,6th) channel down respectively when it is high. pd1,pd2,pd3,pd4,pd5 and pd6 have absolutely no relations among them. allpd makes all of the blocks disable regardless of pdac[5:0]. the minimum pulse width low of allpd should be longer than 1ms. the minimum pulse width low of pdac<5:0> should be longer than 50ns. the minimum pulse width low of allpd and pdac<5:0> should be longer than 20ns. io clk d[9:0] 1 clocks pipeline delay data(1111111111) 0000000000 t r ts tpwh tpwl 0000000000 tclk tset t f td high low vout(p-p) 0v clk ts th td d[9:0] data[2] data[3] data[1] io vout[2] vout[1] clk d[9:0] data1(1111111111) io pdac tpn tpf 0v vout(pp) vout[2] 0-5 t sell t spwl t det_val sel[2:0] pre dtout 9/15
sec asic dac1243x-al 10bit 30msps hexa channel dac analog location description cc 0.1 f ct 10 f r set 658 ? r l1 37.5 ? r l2 37.5 ? r l3 37.5 ? v bia s 0.7v core evaluation guide * you must use more than two pads for vdd33aa11 'cause it's current is more than about 81ma. select test path host dsp core 10 10 10 10 10 10 mux io2 io3 io1 r l1 r l2 r l3 bw1243x-al d1[9:0] d2[9:0] d3[9:0] pdac[5:0] vbias 0.7v r set irset allpd cc ccomp vdd33aa1 clk clk(30mhz) vdd25ad1 vss25ad1 vdd25aa1 vss25aa1 vbba 2.5v l1 ct + 2.5v l2 ct + cc cc d4[9:0] d5[9:0] d6[9:0] 10 10 10 10 10 10 10 10 10 io5 io6 io4 r l4 r l5 r l6 pre sel[2:0] control input dtout 10 / 15
sec asic dac1243x-al 10bit 30msps hexa channel dac analog location description cc 0.1 f ct 10 f r set 658 ? r l1 37.5 ? r l2 37.5 ? r l3 37.5 ? v bia s 0.7v core evaluation guide * you must use more than two pads for vdd33aa11 'cause it's current is more than about 81ma. input pad normal operation logic normal operation logic clk_mux normal operation logic clk_mux input pad normal operation logic normal operation logic clk_mux software dc control normal operation logic clk_mux normal operation logic clk_mux normal operation logic clk_mux normal operation logic clk_mux software dc control software dc control software dc control software dc control software dc control software dc control output pad output pad output pad output pad output pad output pad clk d1[9:0] d1[9:0] d1[9:0] d1[9:0] d1[9:0] d1[9:0] io6 io5 io4 io3 io2 io1 dac1243x_al 11 / 15
sec asic dac1243x-al 10bit 30msps hexa channel dac analog 1. about testability if you want to test it over full spec via all channel in main chip(that is, when it is used as a block of main chip) you must add many pins(for 60pins of digital inputs, 6pins of analog outputs, etc) at the main chip to test this dac block. but usually it is nearly impossble 'cause the total number of pins at main chip is limited. so more efficient method for testing this dac block is needed. we offer two ways of testing efficiently here as a reference. but remember this is not the best thing. you can test it by your own testing method. 2. first method of testability the first way is adding only extra 10pads for 10bit parallel digital inputs and 3pads for channel selecting and path selecting. you can check six channels one by one, that is you can test only one channel at one time. therefore you can test all three channels by turn but cannot check all channel at one time. and this method needs extra mux and switch blocks for testing. furthermore we can assure all channels by testing only one channel because all the six channels have same architecture and share the same analog reference block(opamp, cm, bgr). this characteristic makes it simple to test this dac block(when it is embedded in main chip) by adding another 10pads for parallel digital inputs and 3pads for selecting one channel analog switch block of dac out of three channels. 3. second method of testability if above extra 13pads are burden on you, then you can test it by this second method to reduce the extra pads for testing. what is different from above method is that this way needs only 2 extra pads(one for 1bit serial digital input and the other for clock signal), but you must insert extra serial to parallel converter block for converting 1bit 10times high speed digital input to 10bit parallel digital inputs. and this block may need considerable area. and this method also needs extra 3pads for channel selecting and path selecting. 4 analysis the voltage applied to vbias is measured at irset node . and the voltage value is proportioned to the reference current value of resistor which is connected to irset node. so you can estimate the full scale current value by measuring the voltage, and check the dc characteristics of the opamp. for reference, as v bia s voltage applied to vbias pin is given at irset node, the current flowing through r set resistor(connected to irset pin) is given as v ref /r set . if the voltage applied to vbias pin is not same with irset node, you can say "this dac chip does not work properly", because the internal opamp block makes the two node voltage(ifef pin, vbias pin) equal. and you have to check the comp node to see the desired voltage on it. if the desired voltage is not measured, you can check the dac output by appling a desired voltage to the comp pin instead of compensation capacitor directly. if you use internal reference voltage(bgr's output voltage) instead of external vbias by setting the bgrsw low, you can check the bgr's output by checking the vbias pin voltage. 12 / 15
sec asic dac1243x-al 10bit 30msps hexa channel dac analog pc board layout considerations ? pc board considerations to minimize noise on the power lines and the ground lines, the digital inputs need to be shielded and decoupled. this trace length between groups of vdd (vdd33aa1,vdd33ad1) pins short as possible so as to minimize inductive ringing. ? supply decoupling and planes for the decoupling capacitor between the power line and the ground line, 0.1 f ceramic capacitor is used in parallel with a 10 f tantalum capacitor. the digital power plane(vdd33ad1) and analog power plane(vdd33aa1) are connected through a ferrite bead, and also the digital ground plane(vss33ad1) and the analog ground plane(vss33aa1). this ferrite bead should be located within 3inches of the dac1243x-al. the analog power plane supplies power to the dac1243x-al of the analog output pin and related devices. core layout guide (optional) layout dac core replacement ? it is recommended that you use thick analog power metal. when connecting to pad, the path should be kept as short as possible, and use branch metal to connect to the center of analog switch block. ? it is recommended that you use thick analog output metal(at least more than 25 m) when connecting to pad, and also the path length should be kept as short as possible. ? digital power and analog power are separately used. ? when it is connected to other blocks, it must be double shielded using n-well and p+ active to remove the substrate and coupling noise. in that case, the power metal should be connected to pad directly. ? bulk power is used to reduce the influence of substrate noise. ? you must use more than two pins for vdd33aa11 because it require much current dissipation(about 93ma) ? it is recommended that analog metal line(including irset,vbias,io[1:3],iob[1:3]) and analog power metal line should be layouted alone and should not mixed with other noisy digital metal lines. ? if this core is used as a function block in larger main chip, you can join digital power metal of this core with the main digital power instead of using new digital power pad for this core. but you must use new analog power pad for the analog power of this core. ? analog signal interconnect to minimized noise pickup and reflections due to impedance mismatch, the dac1243x-al should be located as close as possible to the output connector. the line between dac output and monitor input should also be regarded as a transmission line. due to the fact, it can cause problems in transmission line mismatch. as a solution to these problems, the double-termination methods used. by using this, both ends of the termination lines are matched, providing an ideal, non-reflective system. 13 / 15
sec asic dac1243x-al 10bit 30msps hexa channel dac analog dc / ac electrical characteristic characteristics min typ max unit remarks supply voltage v power dissipation mw resolution bits analog output voltage v operating temperature c output load capacitor f output load resistor ? integral non-linearity error lsb differential non-linearity error lsb maximum conversion rate mhz voltage output dac reference voltage top bottom v analog output voltage range v digital input format binary code or 2's complement code current output dac analog output maximum current ma analog output maximum signal frequency mhz reference voltage v external resistor for current setting(rset) ? pipeline delay sec feedback request we appreciate your interest in out products. if you have further questions, please specify in the attached form. thank you very much. 14 / 15 - do you want to interal reference voltage(bgr)? - which do you want to serial input type or parallel input type? - do you need 3.3v and 5v power supply in your system? - how many channels do you need(bw1221l is dual channel dac)?
sec asic dac1243x-al 10bit 30msps hexa channel dac analog history card version date modified items comments ver 1.0 newly registered by circuit designer koo hyung-woan ver 1.3 00.08.05 port name change (pdac[6:1]->pdac[5:0]), add history card 15 / 15

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