unisonic technologies co., ltd TL494 linear integrated circuit www.unisonic.com.tw 1 of 7 copyright ? 2009 unisonic technologies co., ltd qw-r103-004,f voltage mode pwm control circuit ? description the utc TL494 incorporates all the functions required in the construction of a pulse-width modulation switching circuit. designed primarily for switching power supply control or dc-dc convectors, it offers the system s engineer the flexibility to tailor control circuitry to its own application. ? features *complete pwm power control circuitry *uncommitted outputs for 200ma sink or source current *output control selects single ended or push pull operation *internal circuitry prohibits double pulses over total range *easy synchronization lead free:TL494l halogen free:TL494g ? ordering information ordering number normal lead free plating halogen free package packing TL494-d16-t TL494l-d16-t TL494g-d16-t dip-16 tube TL494-s16-r TL494l-s16-r TL494g -s16-r sop-16 tape reel
TL494 linear integrated circuit unisonic technologies co., ltd 2 of 7 www.unisonic.com.tw qw-r103-004,f ? pin configuration ? block diagram error amplifier error amplifier dead time control dead time comparator oscillator pulse steering flip-flop input control 5v reference regulation v ref vcc gnd pwm comparator 0.7ma 1 2 4 5 6 7 8 9 10 11 14 13 12 15 16 t q q q1 q2 r t c t c1 e1 c2 e2
TL494 linear integrated circuit unisonic technologies co., ltd 3 of 7 www.unisonic.com.tw qw-r103-004,f ? absolute maximum ratings (unless otherwise noted all is over operating free air temperature range) parameter symbol ratings unit supply voltage(note 3) v cc 41 v amplifier input voltage v in v cc +0.3 v collector output voltage v out 41 v collector output current i co 250 ma ta=25 c 1000 mw continuous total dissipation derate at ta 25 c p d 9.2 mw/ c junction temperature t j 125 c operating temperature t opr -25 ~ +85 c storage temperature t stg -40 ~ +150 c note 1. absolute maximum ratings are those values beyond which the device could be permanently damaged. absolute maximum ratings are stress ratings only an d functional device operat ion is not implied. 2. all voltage values, except differential voltages are with respect to the network ground terminal. ? recommended operating conditions ratings parameter symbol min max unit supply voltage v cc 7 40 v amplifier input voltage v in -0.3 vcc-2 v collector output voltage v out 40 v collector output current(each transistor) ic 200 ma current into feedback i f 0.3 ma timing capacitor c t 0.47 10000 nf timing resistor r t 1.8 500 k oscillator frequency fosc 1 300 khz operating free-air temperature ta 0 70 c
TL494 linear integrated circuit unisonic technologies co., ltd 4 of 7 www.unisonic.com.tw qw-r103-004,f ? electrical characteristics (over recommended operating fr ee-air temperature range, v cc =15v, f=1khz, unless otherwise specified) parameter symbol test conditions min typ max unit reference section output voltage v out i out =1ma 4.75 5 5.25 v input regulation v in v cc =7v ~ 40v 2 25 mv output regulation v out i out =1 ~ 10ma 1 15 mv output voltage change with temperature ta=min ~ max(note 2) 0.2 1 % short-circuit output current i o(sc) v ref =0 35 ma oscillator section frequency f c t =0.01 f, r t =12k 10 khz standard deviation of frequency all values of v cc c t , r t , t a constant 10 % frequency change with voltage v cc =7v ~ 40v,ta=25 c 0.1 % frequency change with temperature c t =0.01 f, r t =12k , ta=min ~ max 12 % amplifier section input offset voltage error v i(off) v out (pin 3)=2.5v 2 10 mv input offset current i i(off) v out (pin 3)=2.5v 25 250 na input bias current i i(bias) v out (pin 3)=2.5v 0.2 1 a common-mode input voltage range error v cc =7v ~ 40 v -0.3 ~ vcc-2 v open-loop voltage amplification v out =3v, v out =0.5v ~ 3.5v 70 95 db unity-gain bandwidth gb w 800 khz common-mode rejection ratio error cmrr v cc =40v,t a =25 c 65 80 db output sink current(pin 3) i o(sink) v id =-15mv ~ -5v v(pin 3)=0.5v 0.3 0.7 ma output source current(pin 3) i o(source) v id =15mv ~ -5v, v(pin 3)=3.5v -2 ma output section collector off-state current i c(off) v ce =40v, v cc =40v 2 100 a emitter off-state current i e(off) v cc =v c =40v, v e =0 -100 a common-emitter v e =0, i c =200ma 1.1 1.3 v collector -emitter saturation voltage emitter-follower v c =15v, i e =-200ma 1.5 2.5 output control input current v in =v ref 3.5 ma dead time control section input bias (pin 4) i i(bias) v in =0 ~ 5.25v -2 -10 a maximum duty cycle, each output v in (pin 40)=0 45 % input threshold voltage(pin 4) v thr zero duty cycle 3 3.3 v maximum duty cycle 0 pwm comparator section input threshold voltage(pin 3) v thr zero duty cycle 4 4.5 v input sink current (pin 3) i i(sink) v(pin 3)= 0.7v 0.3 0.7 ma total device v cc =15v 6 10 ma standby supply current v cc =40v i st-by pin 6 at v ref , all other inputs and outputs open 9 15 average supply current v(pin 4)=2v 7.5 ma switching characteristics, ta=25 c output voltage rise time t r 100 200 ns output voltage fall time t f common-emitter configuration 25 100 ns output voltage rise time t r 100 200 ns output voltage fall time t f emitter-follower configuration 40 100 ns note 1:all typical values except for temperature coefficient are at ta=25 c. note 2:for conditions shown as min or max, use appr opriate value under recommended operating conditions. note 3:duration of the short-circ uit should not exceed one second. note 4:standard deviation is a measur e of the statistical distribution t he mean as derived from the formula:
TL494 linear integrated circuit unisonic technologies co., ltd 5 of 7 www.unisonic.com.tw qw-r103-004,f ? test circuit dead-time feedback r t c t error amplifier output control gnd e2 c2 e1 c1 vcc test inputs 1 2 3 4 5 6 7 8 9 10 11 12 14 15 16 13 vcc=15v 2w 150 2w 150 output 1 output 2 v ref output 50k 12k 0.01 f voltage at c1 dead-time control input feedback voltage at c2 voltage at ct threshold voltage threshold voltage fig 1. operational test circuit and waveforms
TL494 linear integrated circuit unisonic technologies co., ltd 6 of 7 www.unisonic.com.tw qw-r103-004,f ? test circuit(cont.) vin error amplifier 1 2 15 16 vref error amplifier feedback terminal fig 2. amplifier characteristics
TL494 linear integrated circuit unisonic technologies co., ltd 7 of 7 www.unisonic.com.tw qw-r103-004,f ? typical performance characteristics utc assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice.
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