techni cal data 2011, february, rev. 0 2 pwm control circuit the il494 incorporates on a single monolithic chip all the functions required in the construction of a pulse - width - modulation control circuit. designed primarily for power supply control, the il494 contains an on - chip 5 - volt regul ator, two error amplifiers, adjustable oscillator, dead - time control comparator, pulse - steering flip - flop, and output - control circuitry. the uncommitted output transistors provide either common - emitter or emitter - follower output capability. push - pull or si ngle - ended output operation may be selected through the output - control function. the architecture of the il494 prohibits the possibility of either output being pulsed twice during push - pull operation. feature ? complete pwm power con trol circuitry ? uncommitted outputs for 200 ma sink or source ? output control selects single - ended or push - pull operation ? internal circuitry prohibits double pulse at either output ? internal regulator provides a stable 5 v reference supply ? variable dead - time provides control over total range pin assignment il494 function table output control output function grounded single - ended or parallel output at v ref normal push - pull operation logic diagram orderi ng i nform ati on device operating temperature range package shipping il494n t a = -20 to 85 c for all packages plastic dip - 16 tube il494d sop - 16 tube il494d t sop - 16 tape& reel
i l 494 2011, february, rev. 0 2 maximum ratings symb ol parameter value unit v cc supply voltage 41 v v i amplifier input voltage v cc +0.3 v v o collector output voltage 41 v collector output current 250 ma tstg storage temperature - 65 to +150 c * stresses beyond those listed under ?absolute maximum ratings? may cause permanent damage to the device. these are stress ratings only and functional operation of the device at these or any other condi tions beyond those indicated under ?recommended operating conditions? is not implied. exposure to absolute - maximum - rated conditions for extended periods may affect device reliability. recommended operating conditions symbol parameter min max unit v cc supply voltage 7 40 v v i amplifier input voltage - 0.3 v cc - 2 v v o collector output voltage 40 v collector output current (each transistor) 200 ma current into feed back terminal 0.3 ma c t timing capacitor 0.47 10.000 nf r t timing resistor 1.8 500 k ? oscillator frequency 1 300 khz t a operating free - air temperature - 20 +85 c
i l 494 2011, february, rev. 0 2 electrical characteristics (temperature - 20 85 c, v cc = 15 v, f=10 khz)) symbol parameter test conditions min max unit reference section v ref output voltage i o =1 ma 4. 90 5. 10 v v regin output regulation v cc =7 v to 40 v, t a =25 c 25 mv v regout input regulation i o =1 to 10 ma, t a =25 c 15 mv ? v ref output voltage change with temperature t a = - 20 c to 85 c 1 % i sc short - circuit output current (note 1) v ref=0 50 ma oscillator section f osc frequency c t =0.01 f, r t =12 k ? 6 14 khz f osc standard deviation of frequency (note 2) all values of v cc , c t , r t , t a constant 15 % f osc( ? v) frequency change with voltage v cc = 7 v to 40 v, t a =25 c 10 % f osc( ? t) frequency change with temperature c t =0.01 f, r t =12 k ? t a = - 20 c to 85 c 2 % dead time control section i ib(2t) input bias current (pin 4) v i = 0 to 5.25 v - 10 a dc max maximum duty cycle, each output v i(pin 4) =0 v 45 % v thd input threshold voltage z ero duty cycle 3.3 v (pin 4) maximum duty cycle 0 error amp section v io input offset voltage v o(pin 3) =2.5 v 10 mv i io input offset current v o(pin 3) =2.5 v 250 na i ib input bias current v o(pin 3) =2.5 v 1 a common - mode input v cc = 7 v to 40 v low - 0.3 v voltage range high v cc - 2 a vol open - loop voltage amplification ? v o =3 v, v o =0.5 to 3.5 v 70 db f b unity - gain bandwidth 100 khz cmrr common - mode rejection ratio v cc =40 v, t a =25 c 65 db i o output sink current (pin 3) v id = - 15 mv to - 5 v, v o(pin 3) =0.7 v 0.3 ma i o+ output source current (pin 3) v id =15 mv to 5 v, v o(pin 3) =3.5 v - 2 ma
i l 494 2011, february, rev. 0 2 electrical characteristics (temperature - 20 85 c, v cc = 15 v, f=10 khz)) symbol parameter test conditions min max unit pwm comparator section v thp input threshold voltage (pin 3) zero duty cycle 4.5 v i i input sink current (pin 3) v o(pin 3) =0.7 v 0.3 ma switching characteristics t rc output voltage rise time common - emitter configuration 200 ns t fc output voltage fall time common - emitter c onfiguration 100 ns t rf output voltage rise time emitter - follower configuration 200 ns t ff output voltage fall time emitter - follower configuration 100 ns output section i c(off) collector off - state current v ce =40 v, v cc =40 v 100 a i e(off) emitter off - state current v cc =v c =40 v, v e =0 - 100 a v sat collector - emitter common - emitter v e =0, i c =200 ma 1.3 v saturation voltage emitter - follower v c =15 v, i e = - 200 ma 2.5 i och output control input current v i =v ref 3.5 ma total device i cc standby supply current all other inputs & v cc =15 v 10 ma outputs open v cc =40 v 15 i cca average supply current v (pin 4) =2 v 17 ma notes: 1. duration of the short circuit should not exceed one second. 2. standard deviation is a measure of the statistical disributi on about the mean as derived from the formula n (x n - x) 2 n=1 = n ? 1
i l 494 2011, february, rev. 0 2 typical application pulse width modulated step - down converter
i l 494 2011, february, rev. 0 2 parameter measurement information 1. dead time and feedback control 2. error amplifier character istics 3. common - emitter configuration 4. emitter - follower configuration
i l 494 2011, february, rev. 0 2 typical performance curves figure 1 ? oscillator frequency v s. timing resistance figure 2 ? open loop voltage gain and phase v s . frequency figure 3 ? percent dead time vs. oscillator frequency figure 4 ? percent duty cyc le vs. dead - time control voltage
i l 494 2011, february, rev. 0 2 figure 5 ? emitter - follower configuration output - saturation voltage vs. emitter current figu re 6 ? common - emitter configuration output - saturation voltage vs. collector current fugure 7 ? standby - supply current vs. supply voltage
i l 494 2011, february, rev. 0 2 n suffix plastic dip (ms - 001bb) symbol min max a 18.67 19.69 b 6.1 7.11 c 5.33 d 0.36 0.56 f 1.14 1.78 g h j 0 10 k 2.92 3.81 no tes : l 7.62 8.26 1. dimensions ?a?, ?b? do not include mold flash or protrusions. m 0.2 0.36 maximum mold flash or protrusions 0.25 mm (0.010) per side. n 0.38 d s uffix s oic (ms - 012ac) symbol min max a 9.8 10 b 3.8 4 c 1.35 1.75 d 0.33 0.51 f 0.4 1.27 g h j 0 8 no tes : k 0.1 0.25 1. dimensions a and b do not include mold flash or protrusion. m 0.19 0.25 2. maximum mold flash or protrusion 0.15 mm (0.006) per side p 5.8 6.2 for a; for b ? 0.25 mm (0.010) per s ide. r 0.25 0.5 5.72 2.54 7.62 1.27 dimens ion, mm dimens ion, mm a b h c k c m j f m p g d r x 45 seating plane 0.25 (0.010) m t -t- 1 16 8 9 l h m j a b f g d se ati ng plane n k 0.25 (0.010) m t -t- c 1 16 8 9
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