unisonic technologies co., ltd tl494 linear integrated circuit www.unisonic.com.tw 1 of 7 copyright ? 2012 unisonic technologies co., ltd qw-r103-004,g 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 dip-16 sop-16 ? ordering information ordering number package packing lead free halogen free tl494l-d16-t tl494g-d16-t dip-16 tube tl494l-s16-r tl494g-s16-r sop-16 tape reel tl494l-s16-t TL494G-S16-T sop-16 tube
tl494 linear integrated circuit unisonic technologies co., ltd 2 of 7 www.unisonic.com.tw qw-r103-004,g ? 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,g ? absolute maximum ratings (unless otherwise specified) 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 power dissipation (t a =25 c ) p d 1000 mw derate at t a 25 c 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 parameter symbol min typ 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) i c 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 f osc 1 300 khz operating free-air temperature t a 0 70 c ? 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 oscillator section frequency f c t =0.01 c 0.1 % frequency change with temperature c t =0.01 ta=min ~ max 12 %
tl494 linear integrated circuit unisonic technologies co., ltd 4 of 7 www.unisonic.com.tw qw-r103-004,g ? electrical characteristics(cont.) parameter symbol test conditions min typ max unit 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 ~ v cc -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 collector -emitter saturation voltage common-emitter v e =0, i c =200ma 1.1 1.3 v 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 standby supply current v cc =15v i st-by pin 6 at v ref , all other inputs and outputs open 6 10 ma v cc =40v 9 15 average supply current v(pin 4)=2v 7.5 ma switching characteristics, ta=25 c output voltage rise time t r common-emitter configuration 100 200 ns output voltage fall time t f 25 100 ns output voltage rise time t r emitter-follower configuration 100 200 ns output voltage fall time t f 40 100 ns notes: 1. all typical values except fo r temperature coefficient are at ta=25 c. 2. for conditions shown as min or max, use appr opriate value under recommended operating conditions. 3. duration of the short-circuit should not exceed one second. 4. standard deviation is a measure of the statistical distribution the mean as derived from the formula:
tl494 linear integrated circuit unisonic technologies co., ltd 5 of 7 www.unisonic.com.tw qw-r103-004,g ? 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,g ? 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,g ? 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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