View TL494_710331.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

device operating temperature range package semiconductor technical data switchmode pulse width modulation control circuit ordering information TL494cn TL494in t a = 0 to +70 c t a = 25 to +85 c plastic plastic pin connections order this document by TL494/d n suffix plastic package case 648 c t r t ground c1 1 inv input c2 q2 e2 e1 1 0.1 v oscillator v cc 5.0 v ref (top view) noninv input inv input v ref output control v cc noninv input compen/pwn comp input deadtime control error amp + 2 3 4 5 6 7 89 10 11 12 13 14 15 16 2 error amp + q1 d suffix plastic package case 751b (so16) TL494cd so16 1 motorola analog ic device data
?
the TL494 is a fixed frequency, pulse width modulation control circuit designed primarily for switchmode power supply control. ? complete pulse width modulation control circuitry ? onchip oscillator with master or slave operation ? onchip error amplifiers ? onchip 5.0 v reference ? adjustable deadtime control ? uncommitted output transistors rated to 500 ma source or sink ? output control for pushpull or singleended operation ? undervoltage lockout maximum ratings (full operating ambient temperature range applies, unless otherwise noted.) rating symbol TL494c TL494i unit power supply voltage v cc 42 v collector output voltage v c1 , v c2 42 v collector output current (each transistor) (note 1) i c1 , i c2 500 ma amplifier input voltage range v ir 0.3 to +42 v power dissipation @ t a 45 c p d 1000 mw thermal resistance, junctiontoambient r q ja 80 c/w operating junction temperature t j 125 c storage temperature range t stg 55 to +125 c operating ambient temperature range TL494c TL494i t a 0 to +70 25 to +85 c derating ambient temperature t a 45 c note: 1. maximum thermal limits must be observed. ? motorola, inc. 1996 rev 1
TL494 2 motorola analog ic device data recommended operating conditions characteristics symbol min typ max unit power supply voltage v cc 7.0 15 40 v collector output voltage v c1 , v c2 30 40 v collector output current (each transistor) i c1 , i c2 200 ma amplified input voltage v in 0.3 v cc 2.0 v current into feedback terminal l fb 0.3 ma reference output current l ref 10 ma timing resistor r t 1.8 30 500 k w timing capacitor c t 0.0047 0.001 10 m f oscillator frequency f osc 1.0 40 200 khz electrical characteristics (v cc = 15 v, c t = 0.01 m f, r t = 12 k w , unless otherwise noted.) for typical values t a = 25 c, for min/max values t a is the operating ambient temperature range that applies, unless otherwise noted. characteristics symbol min typ max unit reference section reference voltage (i o = 1.0 ma) v ref 4.75 5.0 5.25 v line regulation (v cc = 7.0 v to 40 v) reg line 2.0 25 mv load regulation (i o = 1.0 ma to 10 ma) reg load 3.0 15 mv short circuit output current (v ref = 0 v) i sc 15 35 75 ma output section collector offstate current (v cc = 40 v, v ce = 40 v) i c(off) 2.0 100 m a emitter offstate current v cc = 40 v, v c = 40 v, v e = 0 v) i e(off) 100 m a collectoremitter saturation voltage (note 2) commonemitter (v e = 0 v, i c = 200 ma) emitterfollower (v c = 15 v, i e = 200 ma) v sat(c) v sat(e) 1.1 1.5 1.3 2.5 v output control pin current low state (v oc 0.4 v) high state (v oc = v ref ) i ocl i och 10 0.2 3.5 m a ma output voltage rise time commonemitter (see figure 12) emitterfollower (see figure 13) t r 100 100 200 200 ns output voltage fall time commonemitter (see figure 12) emitterfollower (see figure 13) t f 25 40 100 100 ns note: 2. low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient temperature as possible.
TL494 3 motorola analog ic device data electrical characteristics (v cc = 15 v, c t = 0.01 m f, r t = 12 k w , unless otherwise noted.) for typical values t a = 25 c, for min/max values t a is the operating ambient temperature range that applies, unless otherwise noted. characteristics symbol min typ max unit error amplifier section input offset voltage (v o (pin 3) = 2.5 v) v io 2.0 10 mv input offset current (v o (pin 3) = 2.5 v) i io 5.0 250 na input bias current (v o (pin 3) = 2.5 v) i ib 0.1 1.0 m a input common mode voltage range (v cc = 40 v, t a = 25 c) v icr 0.3 to v cc 2.0 v open loop voltage gain ( d v o = 3.0 v, v o = 0.5 v to 3.5 v, r l = 2.0 k w) a vol 70 95 db unitygain crossover frequency (v o = 0.5 v to 3.5 v, r l = 2.0 k w ) f c 350 khz phase margin at unitygain (v o = 0.5 v to 3.5 v, r l = 2.0 k w ) f m 65 deg. common mode rejection ratio (v cc = 40 v) cmrr 65 90 db power supply rejection ratio ( d v cc = 33 v, v o = 2.5 v, r l = 2.0 k w ) psrr 100 db output sink current (v o (pin 3) = 0.7 v) i o 0.3 0.7 ma output source current (v o (pin 3) = 3.5 v) i o + 2.0 4.0 ma pwm comparator section (test circuit figure 11) input threshold voltage (zero duty cycle) v th 2.5 4.5 v input sink current (v (pin 3) = 0.7 v) i i 0.3 0.7 ma deadtime control section (test circuit figure 11) input bias current (pin 4) (v pin 4 = 0 v to 5.25 v) i ib (dt) 2.0 10 m a maximum duty cycle, each output, pushpull mode (v pin 4 = 0 v, c t = 0.01 m f, r t = 12 k w ) (v pin 4 = 0 v, c t = 0.001 m f, r t = 30 k w ) dc max 45 48 45 50 50 % input threshold voltage (pin 4) (zero duty cycle) (maximum duty cycle) v th 0 2.8 3.3 v oscillator section frequency (c t = 0.001 m f, r t = 30 k w ) f osc 40 khz standard deviation of frequency* (c t = 0.001 m f, r t = 30 k w ) s f osc 3.0 % frequency change with voltage (v cc = 7.0 v to 40 v, t a = 25 c) d f osc ( d v) 0.1 % frequency change with temperature ( d t a = t low to t high ) (c t = 0.01 m f, r t = 12 k w ) d f osc ( d t) 12 % undervoltage lockout section turnon threshold (v cc increasing, i ref = 1.0 ma) v th 5.5 6.43 7.0 v total device standby supply current (pin 6 at v ref , all other inputs and outputs open) (v cc = 15 v) (v cc = 40 v) i cc 5.5 7.0 10 15 ma average supply current (c t = 0.01 m f, r t = 12 k w , v (pin 4) = 2.0 v) (v cc = 15 v) (see figure 12) 7.0 ma * standard deviation is a measure of the statistical distribution about the mean as derived from the formula, s n n = 1 s (x n x ) 2 n 1
TL494 4 motorola analog ic device data figure 1. representative block diagram figure 2. timing diagram 6 r t c t 5 4 deadtime control oscillator 0.12v 0.7v 0.7ma + 1 + + + 2 d q ck + + 3.5v 4.9v 13 reference regulator q1 q2 8 9 11 10 12 v cc v cc 12 3 1516 14 7 error amp 1 feedback pwm comparator input ref. output gnd uv lockout flip flop output control error amp 2 deadtime comparator pwm comparator q capacitor c t feedback/pwm comp. deadtime control flipflop clock input flipflop q flipflop q output q1 emitter output q2 emitter output control this device contains 46 active transistors.
TL494 5 motorola analog ic device data applications information description the TL494 is a fixedfrequency pulse width modulation control circuit, incorporating the primary building blocks required for the control of a switching power supply. (see figure 1.) an internallinear sawtooth oscillator is frequency programmable by two external components, r t and c t . the approximate oscillator frequency is determined by: f osc 1.1 r t ? c t for more information refer to figure 3. output pulse width modulation is accomplished by comparison of the positive sawtooth waveform across capacitor c t to either of two control signals. the nor gates, which drive output transistors q1 and q2, are enabled only when the flipflop clockinput line is in its low state. this happens only during that portion of time when the sawtooth voltage is greater than the control signals. therefore, an increase in controlsignal amplitude causes a corresponding linear decrease of output pulse width. (refer to the timing diagram shown in figure 2.) the control signals are external inputs that can be fed into the deadtime control, the error amplifier inputs, or the feedback input. the deadtime control comparator has an effective 120 mv input offset which limits the minimum output deadtime to approximately the first 4% of the sawtoothcycle time. this would result in a maximum duty cycle on a given output of 96% with the output control grounded, and 48% with it connected to the reference line. additional deadtime may be imposed on the output by setting the deadtimecontrol input to a fixed voltage, ranging between 0 v to 3.3 v. functional table input/output controls output function f out f osc = grounded singleended pwm @ q1 and q2 1.0 @ v ref pushpull operation 0.5 the pulse width modulator comparator provides a means for the error amplifiers to adjust the output pulse width from the maximum percent ontime, established by the deadtime control input, down to zero, as the voltage at the feedback pin varies from 0.5 v to 3.5 v. both error amplifiers have a common mode input range from 0.3 v to (v cc 2v), and may be used to sense powersupply output voltage and current. the erroramplifier outputs are active high and are ored together at the noninverting input of the pulsewidth modulator comparator. with this configuration, the amplifier that demands minimum output on time, dominates control of the loop. when capacitor c t is discharged, a positive pulse is generated on the output of the deadtime comparator, which clocks the pulsesteering flipflop and inhibits the output transistors, q1 and q2. with the outputcontrol connected to the reference line, the pulsesteering flipflop directs the modulated pulses to each of the two output transistors alternately for pushpull operation. the output frequency is equal to half that of the oscillator. output drive can also be taken from q1 or q2, when singleended operation with a maximum ontime of less than 50% is required. this is desirable when the output transformer has a ringback winding with a catch diode used for snubbing. when higher outputdrive currents are required for singleended operation, q1 and q2 may be connected in parallel, and the outputmode pin must be tied to ground to disable the flipflop. the output frequency will now be equal to that of the oscillator. the TL494 has an internal 5.0 v reference capable of sourcing up to 10 ma of load current for external bias circuits. the reference has an internal accuracy of 5.0% with a typical thermal drift of less than 50 mv over an operating temperature range of 0 to 70 c. figure 3. oscillator frequency versus timing resistance 500 k 100 k 10 k 1.0 k 500 1.0 k 2.0 k 5.0 k 10 k 20 k 50 k 100 k 200 k 500 k 1.0 m r t, timing resistance ( w ) , oscillator frequency (hz) f osc v cc = 15 v 0.01 m f 0.1 m f c t = 0.001 m f
TL494 6 motorola analog ic device data figure 4. open loop voltage gain and phase versus frequency figure 5. percent deadtime versus oscillator frequency figure 6. percent duty cycle versus deadtime control voltage 1.0 10 100 1.0 k 10 k 100 k 1.0 m , open loop voltage gain (db) vol f, frequency (hz) a vol 0 20 40 60 80 100 120 140 160 180 , excess phase (degrees) f f v cc = 15 v d v o = 3.0 v r l = 2.0 k w a figure 7. emitterfollower configuration output saturation voltage versus emitter current 500 k 1.0 k 10 k 100 k 500 k f osc , oscillator frequency (hz) % dt, percent deadtime (each output) c t = 0.001 m f 0.001 m f 0 1.0 2.0 3.0 3.5 v dt , deadtime control voltage (iv) % dc, percent duty cycle (each output) v cc = 15 v v oc = v ref 1. c t = 0.01 m f 2. r t = 10 k w 2. c t = 0.001 m f 2. r t = 30 k w 2 1 figure 8. commonemitter configuration output saturation voltage versus collector current 0 100 200 300 400 i e, emitter current (ma) , saturation voltage (v) ce(sat) v 0 100 200 300 400 i c , collector current (ma) ce(sat) , saturation voltage (v) v figure 9. standby supply current versus supply voltage 0 5.0 10 15 20 25 30 35 40 cc , supply current (ma) v cc , supply voltage (v) i 120 110 100 90 80 70 60 50 40 30 20 10 0 20 18 16 14 12 10 8.0 6.0 4.0 2.0 0 50 40 30 20 10 0 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 10 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0
TL494 7 motorola analog ic device data figure 10. erroramplifier characteristics figure 11. deadtime and feedback control circuit figure 12. commonemitter configuration test circuit and waveform + + v in error amplifier under test feedback terminal (pin 3) other error amplifier v ref v cc = 15v 150 2w output 1 output 2 c1 e1 c2 e2 ref out gnd output control (+) (+) () () feedback deadtime error v cc test inputs 50k r t c t 150 2w figure 13. emitterfollower configuration test circuit and waveform r l 68 v c c l 15pf c e q each output transistor 15v 90% v cc 10% 90% 10% t r t f r l 68 v ee c l 15pf c e q each output transistor 15v 90% v ee 10% 90% 10% t r t f gnd
TL494 8 motorola analog ic device data figure 14. erroramplifier sensing techniques figure 15. deadtime control circuit figure 16. softstart circuit figure 17. output connections for singleended and pushpull configurations v o to output voltage of system r1 1 2 v ref r2 + error amp positive output voltage v o = v ref 1 + r 1 3 + 1 2 v ref r2 v o r1 negative output voltage to output voltage of system error amp v o = v ref r 1 r1 r2 output control output q r t c t d t v ref 4 5 6 0.001 30k r 1 r 2 max. % on time, each output 45 80 1 + output q v ref 4 d t c s r s output control singleended q 1 q 2 q c 1.0 ma to 500 ma q e 2.4 v v oc v ref pushpull q 1 q 2 c 1 e 1 c 2 e 2 1.0 ma to 250 ma 1.0 ma to 250 ma output control 0 v oc 0.4 v c 1 e 1 c 2 e 2 r 2 r 2
figure 18. slaving two or more control circuits figure 19. operation with v in > 40 v using external zener figure 20. pulse width modulated pushpull converter r t c t 6 5 v ref r t c t master v ref slave (additional circuits) r t c t 5 6 v in > 40v r s v z = 39v 1n975a v cc 5.0v ref 12 270 gnd 7 +v in = 8.0v to 20v 1 2 3 15 16 + + comp oc v ref dt c t r t gnd e 1 e 2 13144567910 1m 33k 0.01 0.01 v cc c 1 c 2 8 11 47 47 10 + 10k 4.7k 4.7k 15k tip 32 + t 1 1n4934 l 1 1n4934 240 + 50 35v 4.7k 1.0 22 k + +v o = 28 v i o = 0.2 a 12 l1 3.5 mh @ 0.3 a t1 primary: 20t c.t. #28 awg t1 secondary: 12ot c.t. #36 awg t1 core: ferroxcube 1408pl003cb all capacitors in m f TL494 0.001 50 35v 50 25v tip 32 TL494 9 motorola analog ic device data test conditions results line regulation v in = 10 v to 40 v 14 mv 0.28% load regulation v in = 28 v, i o = 1.0 ma to 1.0 a 3.0 mv 0.06% output ripple v in = 28 v, i o = 1.0 a 65 mv pp p.a.r.d. short circuit current v in = 28 v, r l = 0.1 w 1.6 a efficiency v in = 28 v, i o = 1.0 a 71%
TL494 10 motorola analog ic device data figure 21. pulse width modulated stepdown converter +v in = 10v to 40v tip 32a 1.0mh @ 2a +v o = 5.0 v i o = 1.0 a 50 10v + 5.1k mr850 0.1 150 5.1k 5.1k 47k 1.0m 0.1 3 2 1 14 15 16 comp + v ref + v cc c 1 c 2 50 50v 0.001 564137910 c t r t d.t. o.c. gnd e 1 e 2 + 47k + 500 10v 150 47 11 12 8 TL494 test conditions results line regulation v in = 8.0 v to 40 v 3.0 mv 0.01% load regulation v in = 12.6 v, i o = 0.2 ma to 200 ma 5.0 mv 0.02% output ripple v in = 12.6 v, i o = 200 ma 40 mv pp p.a.r.d. short circuit current v in = 12.6 v, r l = 0.1 w 250 ma efficiency v in = 12.6 v, i o = 200 ma 72%
TL494 11 motorola analog ic device data outline dimensions n suffix plastic package case 64808 issue r notes: 1. dimensioning and tolerancing per ansi y14.5m, 1982. 2. controlling dimension: inch. 3. dimension l to center of leads when formed parallel. 4. dimension b does not include mold flash. 5. rounded corners optional. a b f c s h g d j l m 16 pl seating 18 9 16 k plane t m a m 0.25 (0.010) t dim min max min max millimeters inches a 0.740 0.770 18.80 19.55 b 0.250 0.270 6.35 6.85 c 0.145 0.175 3.69 4.44 d 0.015 0.021 0.39 0.53 f 0.040 0.70 1.02 1.77 g 0.100 bsc 2.54 bsc h 0.050 bsc 1.27 bsc j 0.008 0.015 0.21 0.38 k 0.110 0.130 2.80 3.30 l 0.295 0.305 7.50 7.74 m 0 10 0 10 s 0.020 0.040 0.51 1.01 d suffix plastic package case 751b05 (so16) issue j notes: 1. dimensioning and tolerancing per ansi y14.5m, 1982. 2. controlling dimension: millimeter. 3. dimensions a and b do not include mold protrusion. 4. maximum mold protrusion 0.15 (0.006) per side. 5. dimension d does not include dambar protrusion. allowable dambar protrusion shall be 0.127 (0.005) total in excess of the d dimension at maximum material condition. 18 16 9 seating plane f j m r x 45 g 8 pl p b a m 0.25 (0.010) b s t d k c 16 pl s b m 0.25 (0.010) a s t dim min max min max inches millimeters a 9.80 10.00 0.386 0.393 b 3.80 4.00 0.150 0.157 c 1.35 1.75 0.054 0.068 d 0.35 0.49 0.014 0.019 f 0.40 1.25 0.016 0.049 g 1.27 bsc 0.050 bsc j 0.19 0.25 0.008 0.009 k 0.10 0.25 0.004 0.009 m 0 7 0 7 p 5.80 6.20 0.229 0.244 r 0.25 0.50 0.010 0.019
TL494 12 motorola analog ic device data motorola reserves the right to make changes without further notice to any products herein. motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. atypicalo parameters which may be provided in motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. all operating parameters, including atypicalso must be validated for each customer application by customer's technical experts. motorola does not convey any license under its patent rights nor the rights of others. motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the motorola product could create a situation where personal injury or death may occur. should buyer purchase or use motorola products for any such unintended or unauthorized application, buyer shall indemnify and hold motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that motorola was negligent regarding the design or manufacture of the part. motorola and are registered trademarks of motorola, inc. motorola, inc. is an equal opportunity/affirmative action employer. how to reach us: usa / europe / locations not listed : motorola literature distribution; japan : nippon motorola ltd.; tatsumispdjldc, 6f seibubutsuryucenter, p.o. box 20912; phoenix, arizona 85036. 18004412447 or 6023035454 3142 tatsumi kotoku, tokyo 135, japan. 038135218315 mfax : rmfax0@email.sps.mot.com touchtone 6 022446609 asia / pacific : motorola semiconductors h.k. ltd.; 8b tai ping industrial park, internet : http://designnet.com 51 ting kok r oad, tai po, n.t., hong kong. 85226629298 TL494/d ?

▲Up To Search▲

Price & Availability of TL494

	To Download TL494 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .