View AT1382AF-GRE_2623128.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 1 features ? low start-up power supply voltage :1.4v(ch4) ? wide supply voltage range from 1.8v to 7v (ch1~4) ? high speed operation is possible: maximum 1 mhz ? supports for up, flyback and up/down sepic conversion (ch1~4) ? totem-pole type output for mosfet ? built-in on/off function ? built-in short-circuit protection. applications ? digital cameras ? ccd imaging devices ? camcorders general description the at1382a is a 4-chan nel pwm dc/dc control ic for low voltage applications with a soft start function and short circuit detection function. this ic is ideal for up conversion, down conversion, and up/down conversion (using a step-up/step- down sepic system with free input and output settings). four channels can be built in the lqfp48 package, each channel be controlled, and soft-start. the at1382a include one comparator to generate low-battery warning outputs. it also contains a gain block that can be used with an external p-channel mosfet to make a low-dropout linear regulator. pin assi g nment ordering information part number package marking at1382af lqfp48 at1382af at1382af _ pbf lqfp48, pb-free at1382af,date code with one bottom line at1382af _ gre lqfp48,green at1382af,date co de with two bottom line aimtron reserves the right without notice to change this circuitry and specifications.
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 2 pin description pin no. pin name i/o function 1 dtc4 i ch4 dead time control 2 fb4 o ch4 error amplifier output 3 in4 i ch4 error amplifier inverted input 4 cs4 - ch4 soft start setting capacitor 5 ctl4 i ch4 on/off control 6 dtc3 i ch3 dead time control 7 fb3 o ch3 error amplifier output 8 in3 i ch3 error amplifier inverted input 9 cs3 - ch3 soft start setting capacitor 10 ctl3 i ch3 on/off control 11 cscp - timer latch short-circ uit detection capacitor input 12 vref o reference 0.9v output 13 gnd p ground 14 gnd p ground 15 vbg test reference test pin 16 vcc p power supply 17 vcc p power supply 18 por test pre-osc change to main-osc indicator 19 rt - oscillation frequency setting resistor 20 ct - oscillation frequency setting capacitor 21 vb o reference 1.8v output 22 ctl i power supply control 23 enld i gain block enable input 24 ct2 test triangular wave osc inverted output test pin 25 ctl2 i ch2 on/off control 26 cs2 - ch2 soft start setting capacitor 27 in2 i ch2 error amplifier inverted input 28 fb2 o ch2 error amplifier output 29 dtc2 i ch2 dead time control 30 ctl1 i ch1 on/off control 31 cs1 - ch1 soft start setting capacitor 32 in1 i ch1 error amplifier inverted input 33 fb1 o ch1 error amplifier output 34 dtc1 i ch1 dead time control 35 lbi i low battery detected input 36 lbo o low battery indicator 37 ai i ldo regulated input 38 ao o ldo drive output 39 out1_1 o ch1 main side output 40 out1_2 o ch1 synchronous rectifier side output 41 out2_1 o ch2 main side output 42 out2_2 o ch2 synchronous rectifier side output 43 n.c. - 44 pvcc p drive output block power supply 45 n.c. - 46 pgnd p drive output block ground 47 out3 o ch3 output 48 out4 o ch4 output
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 3 block diagram
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 4 absolute maximum ratings ratin g parameter symbol condition min max unit power supply voltage vcc -- -- 8 v output current io output pin -- 20 ma output peak current io output pin, duty Q 5% -- 200 ma power dissipation p d ta Q 25 (lqfp-48p) -- 860 mw operation temperature topr -- -30 85 storage temperature tstg -- -55 125 * semiconductor devices can be permanently damaged by applic ation of stress in excess of absolute ratings. do not exceed these ratings. recommended operating conditions value parameter symbol condition min t yp max unit startup power supply voltage vcc ch4 1.4 -- 7 v ch4 1.5 5.0 7 v power supply voltage vcc ch1 to ch3 1.8 5.0 7 v reference voltage output current i or vref pin -1 -- 0 ma vb pin output current i b vb pin -0.5 -- 0 ma input voltage v in in1 to in4 pins 0 -- vcc-1.8 v control input voltage v ctl ctl pin 0 -- 7 v out pin (ch1 to ch3) -- 2 15 ma output current io out pin (ch4) 1 2 15 ma oscillator f osc -- 100 500 1000 khz timing capacitor c t -- 47 100 560 pf timing resistor r t -- 8.2 18 100 k cs ch1 to ch3 -- 0.027 1.0 f soft start capacitor c cs4 ch4 -- 0.47 1.0 f short detection capacitor c scp -- -- 0.1 1.0 f vb pin capacitor c vb -- 0.082 0.1 -- f operating ambient temperature ta -- -30 25 85
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 5 electrical characteristics (ta=25 , vcc=pvcc=5v) measure result parameter symbol condition min. t yp . max. unit reference voltage block [ref] reference voltage v ref 0.88 0.90 0.92 v output voltage temperature stability v ref / v ref ta = -30 to 85 -0.5-% input stability line vcc=1.8v to 7v -10 - 10 mv load stability load vref=0ma to ?1ma -10 - 10 mv shout circuit output current i osc vref=0.7v -20 -5 -1 ma under voltage lockout block [u.v.l.o] threshold voltage(ch1~ch3) v th 1.5 1.6 1.7 v hysteresis width(ch1~ch3) v h -0.2-v reset voltage(ch1~ch3) v rst 1.6 1.7 1.8 v ch4 pre-osc change to main- osc threshold v th2 -1.7-v soft start block [cs] charge current i cs -6.0 -5.0 -4.0 a short circuit detection block [scp] threshold voltage v th 0.65 0.70 0.75 v input source current i cscp -1.5 -1.0 -0.7 a triangular wave oscillator block [osc] oscillator frequency f osc ct=100pf, rt=20k 400 500 600 khz frequency stability for voltage f / fdv vcc=1.8v to 7v - 1 10 % frequency stability for temperature f / fdt ta=-30 to 85 -1-% error amplifier block [error amp](ch1~ch4) threshold voltage v th fb=0.9v 0.69 0.70 0.71 v v t temperature stability v t / v t ta = -30 to 85 -0.5-% input bias current i b in=0v -320 -80 - na voltage gain a v dc - 100 - db
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 6 frequency bandwidth bw a v =0db - 10 - mhz v oh 1.3 1.4 - v output voltage v ol -50200mv output source current i source fb=0.5v - -4.0 -1.0 ma output sink current i sink fb=0.5v 70 140 - a short detect comparator [scp comp] threshold voltage v th ch1 to ch4 0.8 0.9 1.0 v input bias current i b in=0v -320 -80 - na pwm comp. [pwm comp] v t0 duty = 0 % 0.25 0.3 - v threshold voltage(ch4) v tmax duty = 100 % - 0.75 0.80 v v t0 duty = 0 % 0.20 0.25 - threshold voltage(ch1~3) v tmax duty = 100 % - 0.65 0.70 input current i dtc dtc=0.4v -1.0 -0.3 - a output block (ch1,2) [pin 40,42] output source current i source duty R9 5%, out=0v - -130 -80 ma output sink current i sink duty Q 5%, out=5v 65 100 - ma r oh out = -15ma - 18 30 output on resistor r ol out = 15ma - 16 25 output block (ch1 to ch3) [pin 39,41,47] output source current i source duty R9 5%, out=0v - -130 -80 ma output sink current i sink duty Q 5%, out=5v 65 100 - ma r oh out = -15ma - 18 30 output on resistor r ol out = 15ma - 16 25 output block (ch4) [pin 48] output source current i source out=1/2pvcc - -260 -160 ma output sink current i sink out=1/2pvcv 150 260 - ma r oh out = -15ma - 9 15 output on resistor r ol out = 15ma - 9 15 control block [ctl] v ih active mode 1.3 - 7 v ctl input voltage v il standby mode 0 - 0.8 v ctl1 to ctl4 input voltage v ih active mode 1.3 - 7 v
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 7 v il standby mode 0 - 0.8 v input current i ctl ctl = 5v - 5 20 a analog gain block [ao,ai] ai feedback regulation voltage v ao =v out -1.22v 1.20 1.22 1.24 v ai input common-mode range -0.1 - 1.3 v ai input current v ai =1.32v - - 100 na ai to ao voltage gain 70 100 140 v/v ao output sink current v ai =1v, v ao =2v 0.5 2.5 - ma ao output source current v ai =1.5v, v ao =2v 0.5 2.5 - ma enld enable v ih active mode 1.2 - 7 v enld disable v il standby mode 0 - 0.8 v low battery detect block [lbi, lbo] lbi detect threshold 1.20 1.22 1.24 v detect hysteresis -50 +50 mv lbo output voltage low isink=1ma - - 0.4 v lbo output high leakage v lbo =5v -0.011 a general icss ctl=0v - - 10 a standby current icss(o) ctl=0v ctl1=ctl2=ctl3=ct l4="h" --10 a power supply current icc ctl=ctl1=ctl2=ctl 3=ctl4=enld="h" -36ma
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 8 typical application a.
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 9
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 10 b. using at1382a on buck cnverter
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 11 function description 1. power converter functions ? reference voltage block the reference voltage circuit generates a te mperature independence voltage (typical = 0.9v) from the power source, which is used as reference voltage for the ic?s internal circuitry and supply load current above 1ma to external device. ? triangular oscillator block the triangular wave oscillator is generated by timing resistor (rt) and timing capacitor(ct) to incorporate each other. the waveforms ct (amp litude of 0.3v to 0.7v), ct1 (amplitude 0.25v to 0.65v in phase with ct) and ct2 (amplitude 0.25v to 0.65v in inverse phase with ct) are input to the pwm comparator. ? error amplifier block the error amplifier outputs controlling error signal to pwm comparator from sensing dc/dc converter output voltage. in addition , an arbitr ary loop gain can be set by connecting feedback resistor and capacitor from the output pin to inverted input pin of the error amplifier, in order to make a stable phase compensation to the system. ? pwm comparator block the pwm comparator is a voltage-to-pulse width converter for controlling the duty cycle of dc/dc converter. channels 1and 2 main sides, channel 3 and 4 : the comparator keeps the output transistor turn on while the error amplifier output voltage and dtc voltage still higher than the triangular wave voltage. channels 1 and 2 synchronous rectification sides : the comparator keeps the output transistor turn on while the error amplifier output voltage still lower than the triangular wave voltage . ? output block the output block is the totem pole configuration , which could drive external mosfet or transistor. ? battery low detect block the at1382a battery-low comparator open-drain output lbo sinks up to 1ma if the lbi input is below its threshold voltage. connect lbo to power source with a 100k~1m pullup resistor. ? analog gain block the at1382a analog gain block is a voltage amplifier with a gain of 100 and a push-pull output stage with 2ma drive capability. the analog gain block can be used with an external p-channel mosfet pass transistor to build a low-dropout linear regulator. connect enld to high to enable the gain block.
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 12 2. channel control function the channels are turned on and turned off depending on the voltage levels at the ctl, ctl1, ctl2, ctl3 and ctl4. described as follow. voltage level at ctl pin channel on / off state ctl clt1 clt2 clt3 clt4 ch1 ch2 ch3 ch4 l x x x x off (standby state) loff l h off on loff l h h off on on loff l h off on loff l h h h off on on on loff l h off on loff l h h off on on loff l h off on loff h h h h h on on on on x undefined 3. protective functions ? short circuit protection and timer latch the short circuit detection comparator in each ch annel detects the output voltage level of power converter. when any channel output voltage falls be low the short-circuit detection level, there is a constant current bias chargi ng the external capacitor c scp which connected to the cscp pin until the capacitor voltage level reaches ab out 0.7v then turn off the output transistor and disable the ic. it could reset the actuated protection by restart the power source. ? under-voltage lockout protection the under-voltage lockout protection is to disable the ic while the supply voltage transient state or momentary decrease, which may cause the ic to malfunction. to prevent such malfunctions, the under-voltage lockout protection circuit detects a decrease in internal reference voltage with respect to the power supply voltage, turns off the output transistor, and sets the dead time to 100% while holding the cscp pin at the ?l? level. the circuit restores the output transistor to normal when the power source voltage reaches the threshold voltage of the under-voltage lockout protection circuit.
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 13 4. soft start operation when the ctl , ctl1, ctl2, ctl3 and ctl4 terminal s are driven high level at the same time. the driving scheme is described as follow diagram. the capacitor connected to the cs1,cs2,cs3 and cs4 terminal starts charging and provides a soft start by comparing the ch1 to ch4 output voltage .
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 14 ? when the ctl terminal is switch on, then each of the terminals ctl1, ctl2, ctl3, and ctl4 can be switched on or off independently. any of the ctl1, ctl2, ctl3 and ctl4 terminals are driven high level. the driving scheme is described as follow diagram.
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 15 5. soft start setting the soft start operation is determined by the capacitor connected to the cs1~cs4 terminal. consider the input voltage and load current to design the soft start time. the soft start time until the dc/dc converter output voltage reaches 95%. it can calculate the soft start time ts (s). ts (s) = 0.084 * c s ( f) the soft start function of ch1 to ch4 are the same. it could be disabled soft start function by floating cs pin. 6. setting the output voltage ) 1 ( 7 . 0 ) ( cs r ts cs e v ? ? = ? + = k r 6 . 117 6 . 33 6 . 117 6 . 33
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 16 7. setting time constant for time -latch short-circuit protection the scp comparator detects each channel output voltage while the power converter work at normal condition. q1 is turn on, and the voltage leve l of cscp pin is held at low level. if the load of one channel rapidly due to a short of the load, causing the output voltage to drop, the scp comparator output on that channe l goes to "h" level. the transistor q1 to be turned off and the external capacitor c scp to be charged at 1.0 a. the time period of short circuit protection as show below equation. t pe (s): short detection time t pe (s) = 0.7 * c scp ( f) when the c scp is charged to the 0.7v, the timer-latch is set and output is turn off (dead time is set to 100 ). at this point, the timer-latch is closed and the cscp terminal is held at "l" level. it could be disabled short circuit protection function by connecting cscp pin into the ground.
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 17 8. setting the triangular oscillator frequency the triangular oscillator frequency is determined by the timing capacitor (c t ) connected to the ct terminal, and the timing resistor (r t ) connected to the rt terminal. 9. setting the dead time when using step up or sepic or flyback dc/dc converter, it must prevent that output transistor works at full-on state (on duty = 100%). to prev ent this situation, set the maximum duty of these channels. to set it, set the voltage at the dtc terminal by applying a resistive voltage divider to the vref as shown below. when the voltage at the dtc pin is higher than the triangular wave voltage (ct), the output transistor is turned on. the maximum duty calculation formula assuming that triangular wave amplitude = ? v1(ch4=0.45,ch1~3=0.4) and triangular wave minimum voltage = vx (ch4=0.3,ch1~3=0.25). if don't setting maximum duty, connect dtc terminal directly to the vref terminal. 100 1 max ) ( ? ? = v vx vd on duty ) ( ) ( 1000000 ) ( ? = k r pf c khz f t t osc
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 18 10. setting low battery detector threshold voltage the low battery detected threshold voltage is determined by the external resistor connected to the lbi terminal. if vin (battery voltage) under setting threshold voltage, low battery detect output terminal (lbo) is hold at "l" level. the dr iving scheme is described as follow diagram. 11. decrease the output overshoot
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 19 synchronous rectification reference data
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 20
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 21 *if vcc=pvcc=3.3v, the effici ency will decrease about 0.2~05 % because of the n- mosfet ao3400 rds(on) increase.
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 22 typical characteristics
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 23
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 24
at1382a preliminary product information 4-channel dc-dc converter for dsc 2f, no.10, prosperity rd. ii, science-based industrial park, hsinchu 300,taiwan, r.o.c. tel: 886-3-563-0878 www: http://www.aimtron.com.tw fax: 886-3-563-0879 email: service@aimtron.com.tw 25 package outline: lqfp48

▲Up To Search▲

Price & Availability of AT1382AF-GRE

	To Download AT1382AF-GRE Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .