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current mode pwm controller az2842/3/4/5 data sheet 1 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited general description the az2842/3/4/5 are high performance fixed fre- quency current-mode pwm controller series. these integrated circuits ar e optimized fo r off-line and dc-dc converter applications with minimum external components. they feature under-voltage lockout (uvlo) circuit with low start-up current, trimmed oscillator for precise duty cy cle control, current sense comparator providing maximum current limiting and a totem pole output stage for increasing output current. in addition, these ics also feature accurate protection against over-temperature, over-current and maximal output power. the az2842 and AZ2844 have uvlo thresholds of 15.5v(on) and 10v(off); the corresponding thresholds for az2843 and az2845 are 8.4 v(on) and 7.8v(off). the az2842 and az2843 can operate approaching 100% duty cycle; AZ2844 and az2845 can operate from zero to 50% duty cycle. these ics are available in 3 packages: soic-8, dip-8 and soic-14. features robust v ref line/load regulation low line regulation : 4mv low load regulation : 4mv high stability of reference voltage over a full temperature range: 0.2mv/ o c operating frequency up to 500khz high pwm frequency stability over a full tem- perature range: 2.5% high pwm frequency stability under a full sup- ply voltage range: 0.2% accurate over-temperature protection with hys- teresis uvlo with hysteresis applications off-line converter dc-dc converter voltage adapter crt monitor power supply desktop power supply dvd/stb power supply figure 1. package types of az2842/3/4/5 soic-8 dip-8 soic-14
current mode pwm controller az2842/3/4/5 data sheet 2 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited figure 2. pin configuration of az2842/3/4/5 (top view) pin description pin number pin name function 8-pin 14-pin 1 1 comp this pin is the error amplifier output and is made available for loop compensation. 23 v fb the inverting input of the erro r amplifier. it is normally connected to the switching power supply output through a resistor divider. 35 i sense a voltage proportional to inductor current is connected to this input. the pwm uses this information to terminat e the output switch conduction. 47 r t /c t the oscillator frequency and maximu m output duty cycle ar e programmed by con- necting resistor r t to v ref and capacitor c t to ground. operation to 500 khz is pos- sible. 5 gnd the combined control circuitry and power ground. 6 10 output this output directly dr ives the gate of a power mosfet. peak currents up to 1.0 a are sourced and sunk by this pin. 712 v cc the positive supply of the control ic. 814 v ref this is the reference output. it pr ovides charging current for capacitor c t through resistor r t . 8 pwr gnd this pin is a separate power ground return that is connected back to the power source. it is used to reduce the effects of switchi ng transient noise on the control circuitry. 11 pwr v c the high output voltage (v oh ) is set by the voltage applied to this pin. with a sepa- rate power source connection, it can reduce the effects of switching transient noise on the control circuitry. 9 gnd this pin is the control circuitry ground return and is connected back to the power source ground. 2,4,6,13 n/c no connection. these pins are not internally connected. p/m package (dip-8/soic-8) (soic-14) pin configuration comp i sense v fb r t /c t 8 v ref 7 v cc 6 output 5 gnd 1 2 3 4 n/c v fb n/c i sense n/c r t /c t comp 14 v ref 13 n/c 12 v cc 11 pwr v c 10 output 9 gnd 8 pwr gnd 1 2 3 4 5 6 7 m14 package
current mode pwm controller az2842/3/4/5 data sheet 3 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited functional block diagram figure 3. functional block diagram of az2842/3/4/5 v cc gnd r t /c t v fb i sense comp v cc (pwr v c ) v ref output a(b) gnd (pwr gnd) a for 8-pin b for 14-pin osc vref good logic over temp protect t internal bias 2r r s/r 5v ref uvlo 2.50v pwn latch current sense comparator error amp 34v 1v 7(12) 5(9) 4(7) 2(3) 1(1) 3(5) 7(11) 8(14) 6(10) s r note: toggle flip-flop used for 2844/45 only (note) 5(8)
current mode pwm controller az2842/3/4/5 data sheet 4 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited package tempera- ture range part number marking id packing type tin lead lead free tin lead lead free soic-8 -40 to 85 o c az2842/3/4/5m az2842/3/4/5m-e1 2842/3/4/5m 2842/3/4/5m-e1 tube az2842/3/4/5mtr az2842/3/4/5mtr-e1 2842/3/4/5m 2842/3/4/5m-e1 tape & reel dip-8 -40 to 85 o c az2842/3/4/5p az2842/3/4/5p-e1 az2842/3/4/5p az2842/3/4/5p-e1 tube soic-14 -40 to 85 o c az2842/3/4/5m14 az2842/3/4/5m14-e1 az2842/3/4/5m14 az2842/3/4/5m14-e1 tube az2842/3/4/5m14tr az2842/3/4/5m14tr-e1 az2842/3/4/5m14 az2842/3/4/5m14-e1 tape & reel the listed part numbers are used during the transition to lead-free products. after the transition completed, lead-free product s will be considered as the "standard" and we will resume the or iginal part numbers. circuit type package m: soic-8 e1: lead free blank: tin lead az284x - tr: tape and reel blank: tube m14: soic-14 p: dip-8 ordering information
current mode pwm controller az2842/3/4/5 data sheet 5 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited parameter symbol value unit supply voltage v cc 30 v output current i o 1 a analog inputs (8-pin: pin2,3, 14-pin: pin3,5) v(ana) -0.3 to 6.3 v error amp output sink current i sink (e.a) 10 ma power dissipation at t a < 25 o c (dip-8) p d (note 3) 1000 mw power dissipation at t a <25 o c (soic-8) p d (note 3) 460 mw power dissipation at t a <25 o c (soic-14) p d (note 3) 725 mw storage temperature range t stg -65 to 150 o c lead temperature (soldering, 10sec) t lead 300 o c note 1: stresses greater than 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 conditions beyond those indicated under "recommended operating cond itions" is not implied. exposure to "absolute max- imum ratings" for extended periods may affect device reliability. note 2: all voltages are with respect to pin 5 and all currents are positive into specified terminal. note 3: board thickness 1.6mm, board dimension 90mm x 90mm. parameter symbol min max unit oscillation fre quency f 500 khz ambient temperature t a -40 85 o c recommended operating conditions absolute maximum ratings (note 1, 2)
current mode pwm controller az2842/3/4/5 data sheet 6 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited parameter symbol condi tions min typ max unit reference section reference output voltage v ref t j =25 o c, i ref =1ma 4.95 5.00 5.05 v line regulation ? v ref 12v v cc 25v 4 15 mv load regulation ? v ref 1ma i ref 20ma 4 15 mv short circuit output current i sc t a =25 o c -100 -180 ma temperature stability 0.2 0.4 mv/ o c total output variation range line, load, temperature 4.90 5.10 v output noise voltage (note 6) 50 v long term stability t a =85 o c, 1000 hours 525mv oscillator section oscillation frequency f t j =25 o c 47 52 57 khz frequency change with voltage ? f/f 12v v cc 25v 0.2 1 % oscillator amplitude v osc pin 4, peak to peak (note 6) 1.7 v temperature stability (note 6) 2.5 % error amplifier section input bias current i bias (note 6) -0.1 -1 a input voltage v i vpin 1=2.5v 2.45 2.50 2.55 v open loop voltage gain a vol 2v v o 4v 65 90 db power supply rejection ratio psrr 12v v cc 25v 60 70 db output sink current i sink vpin2=2.7v, vpin1=1.1v 2 4 ma output source current i source vpin2=2.3v, vpin1=5v -0.5 -0.8 ma high output voltage v oh vpin2=2.3v, r l =15k ? to gnd 5 6 v low output voltage v ol vpin2=2.7v, r l =15k ? to pin 8 0.8 1.1 v current sense section gain gv (note 4, 5) 2.85 3 3.15 v/v maximum input signal v i (max) vpin1=5v(note 4) 0.9 1 1.1 v power supply rejection ratio psrr 12v v cc 25v (note 4, 6) 70 db input bias current i bias -3 -10 a delay to output vpin3 = 0 to 2v (note 6) 150 300 ns output section low output voltage v ol i sink = 20ma 0.1 0.4 v i sink = 200ma 1.4 2.2 v high output voltage v oh i source = 20ma 13 14 v i source = 200ma 12 13 v (v cc =15v, r t =10k ? c t =3.3nf, t a = -40 to 85 o c, unless otherwise specified.) electrical characteristics
current mode pwm controller az2842/3/4/5 data sheet 7 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited parameter symbol conditions min typ max unit rise time t r t j =25 o c, c l =1nf (note 6) 50 150 ns fall time t f t j =25 o c, c l =1nf (note 6) 50 150 ns under -voltage lockout section start threshold v th (st) az2842/AZ2844 14.5 15.5 16.5 v az2843/az2845 7.8 8.4 9.0 v min. operation voltage (after turn on) v opr (min.) az2842/AZ2844 8.5 10.0 11.5 v az2843/az2845 7.0 7.6 8.2 v pwm section max. duty cycle d(max.) az2842/az2843 93 95 100 % d(max.) AZ2844/az2845 46 48 50 % min. duty cycle d(min.) 0 % total standby current section start-up current i st 0.5 1 ma operating supply current i cc (opr) vpin3=vpin2=0v 10 14 ma zener voltage v z i cc =25ma 30 34 v over-temperature protect section shutdown temperature t shut (note 6) 165 o c temperature hysteresis t hys (note 6) 25 o c a= , 0 vpin3 0.8v ? vpin 3 note 4: parameters are tested at trip point of latch with vpin2 = 0. note 5: here gain is defined as: ? vpin 1 note 6: these parameters, although guaranteed, are not 100% tested in production. figure 4. basic test circuit electrical characteristics (continued) 1 2 8 7 az2842 3 45 6 v ref v cc output gnd r t /c t i sense v fb comp v ref v cc output gnd 1k 1w c t 5k i sense adjust 1k error amp adjust 4.7k 100k 2n2222 4.7k r t 0.1 f 0.1 f a
current mode pwm controller az2842/3/4/5 data sheet 8 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited figure 4 is the basic test circuit for az284 x. in testing, the high peak currents associated with capacitive loads necessitate careful grounding techniques. timing and bypa ss capacitors should be c onnected close to pin 5 in a single point ground. the transistor and 5k potentiometer are used to sample the oscillator waveform a nd apply an adjustable ramp to pin 3. figure 7. reference voltage vs. am bient temperature figure 8. start- up current vs. ambient temperature typical performance characteristics figure 5. oscillator dead time vs. timing capacitor figure 6. timing resistor vs. frequency -40-20 0 20406080100120 0.4 0.5 0.6 0.7 0.8 0.9 1.0 az2842 ambient temperature ( o c) start up current (ma) 110100 1 10 0.3 30 3 47 22 4.7 2.2 dead time ( s) timing capacitor (nf) 100 1k 10k 100k 1m 10k 100k 5k 50k c t = 1 n f c t = 1 0 n f rt ( ? ) frequency (hz) c t = 1 0 0 n f -40 -20 0 20 40 60 80 100 120 4.980 4.985 4.990 4.995 5.000 5.005 5.010 5.015 v cc =15v, i o =1ma reference voltage (v) ambient temperature ( o c) electrical character istics (continued)
current mode pwm controller az2842/3/4/5 data sheet 9 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited figure 9. supply current vs. ambient temperature figure 10. output satu ration characteristics figure 11. error amplifier open-loop frequency response -40-20 0 20406080100120 6 7 8 9 10 11 12 13 14 15 16 v cc =15v supply current (ma) ambient temperature ( o c) 0 50 100 150 200 250 300 350 400 450 500 550 600 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 v cc =15v, t a =25 o c saturation voltage (v) output sink current (ma) 10 100 1k 10k 100k 1m 0 10 20 30 40 50 60 70 80 90 voltage gain (db) frequency (hz) v cc =15v, t a =25 o c typical performance ch aracteristics (continued)
current mode pwm controller az2842/3/4/5 data sheet 10 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited typical application figure 12. typical applic ation of az2842/3/4/5 + 8 4 6 3 + + j1 ac 85-265v bridge diode 1n4007*4 r2 270k c14 100 /400v c2 2200p 600v r3 39k 2w d1 byv26e t d3 8tq100 l3 4.5 c9 2200 c10 1000 c11 1 c12 10 z2 sa12a j2 12v/5a c1 47 r4 47 d2 1n4148 u1 az2842/3/4/5 v cc 7 2 1 5 v cc v ref v fb r t /c t comp output gnd i sense u2 pc817 c5 220p r14 130k r13 15k r12 10 z1 1n5819 r7 1k r6 10 q1 irf830 r9 7.5k r10 0.51/1w c6 2200p/600v r5 10k c8 0.22 r15 100 r16 8.2k w1 1k r18 3.9k r17 2k u3 az431 ntc c3 0.1 c4 2.2n + r11 820 c7 680p c15 100p
current mode pwm controller az2842/3/4/5 data sheet 11 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited mechanical dimensions soic-8 unit: mm 8 d 4 4 3 2 r 0 . 1 5 r 0 . 1 5 1.00 0.420.09 4.90.10 1 . 5 5 0 . 2 0 0 . 2 0 . 1 0 0 . 9 0 0.8 6.000.20 0 . 2 2 0 . 0 3 0 . 7 0 0 . 0 2 5 0.32 0 . 2 0 3 . 9 0 0 . 1 0 7 7 8 20:1 d 1.27
current mode pwm controller az2842/3/4/5 data sheet 12 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited mechanical dimens ions (continued) soic-14 unit: mm 8.650.10 1.550.20 7 7 0.70 0.2 0 . 2 5 0.550.05 0.25 (0.20min) 3 2 r0.20 r0.20 20:1 a 0.380.10 45 3.900.10 8 a 8 0 . 2 2 0 . 0 3 9 . 5 8 4 4 depth 0.060.10 2.0 1.27 1.00 1 . 3 0 0.420.09 6 . 0 0 0 . 2 0 + 0 . 0 5 - 0 . 1 0
current mode pwm controller az2842/3/4/5 data sheet 13 dec. 2004 rev. 1. 1 bcd semiconductor manufacturing limited mechanical dimens ions (continued) dip-8 unit: mm 4 6 r0.75 6 . 6 0 0 . 5 0 0.457 0.254 0.13min 2.54 10.0max 0.280.07 1.460.31 7.620.25 4 6 5 3 . 3 0 0 . 3 0 9.20.10 30.150.05 0.7
8f, b zone, 900 yi shan road, shanghai 200233, prc tel: +86-21-6495 9539, fax: +86-2 1-6485 9673 bcd semiconductor (taiwan) company limited room 2210, 22nd fl, 333, keelung road , sec. 1, taipei (110), taiwan important notice bcd semiconductor manufacturing limited reserves the right to make changes without further notice to any pro- ducts or specifications herein. bcd semiconductor manuf acturing limited does not assume any responsibility for use of any its products for any particular purpose, nor does bcd semiconductor manufacturing limited assume any liability arising out of the application or use of any its products or circuits. bcd semiconductor manufacturing limi- ted does not convey any license under its patent rights or other rights nor the rights of others. http://www.bcdsemi.com bcd semiconductor corporation 3170 de la cruz blvd, suite # 105 santa clar a, ca 95054-2411, u.s.a tel : +1-408-988 6388, fax : +1-408-988 638 6 shanghai sim-bcd semiconduct or manufacturing co., ltd. 800 yi shan road, shanghai 200233, prc tel: +86-21-6485-1491, fax: +86-21-5450-0008 advanced analog circuits (shanghai) corporation tel: +886-2-2758 6828, fax: +886-2-2758 6892

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