1 date: 5/27/04 spx2940 1a low dropout voltage regulator ?copyright 2004 sip ex corporation 1a low dropout voltage regulator fixed output, fast response spx2940 description features guaranted 1.5a peak current low quiescent current low dropout voltage of 280mv at 1a extremely tight load and line regulation extremely fast transient response reverse-battery protection internal thermal protection internal short circuit current limit replacement for lm2940, mic2940a, as2940 standard to-220 and to-263 packages the spx2940 is a 1a, accurate voltage regulators with a low drop out voltage of 280mv (typical) at 1a. these regulators are specifically designed for low voltage applications that require a low dropout voltage and a fast transient response. they are fully fault protected against over-current, reverse battery, and positive and negative voltage transients. the spx2940 is offered in 3-pin to-220 & to-263 packages. for a 3a version, refer to the spx29300 data sheet. spx2940 v out v in + 6.8 f + 10 f 1 2 3 figure 1. fixed output linear regulator. typical applications circuit applications powering vga & sound card lcd monitors usb power supply power pc tm supplies smps post-regulator pda or notebook computer high efficiency linear power supplies portable instrumentation constant current regulators cordless telephones automotive electronics now available in lead free packaging 123 spx2940 3 pin to-263 gnd v in v out
2 date: 5/27/04 spx2940 1a low dropout voltage regulator ?copyright 2004 sip ex corporation absolute maximum ratings lead temperature (soldering, 5 seconds) ................................. 260 c storage temperature range ..................................... -65 c to +150 c operating junction temperature range ................... -40 c to +125 c input voltage (note 5) ................................................................... 16v notes: note 1: dropout voltage is defined as the input to output differential when the output voltage drops to 99% of its normal valu e. note 2: v in =v out (nominal) + 1v. for example, use v in =4.3v for a 3.3v regulator. employ pulse-testing procedures to minimize temperature rise. note 3: ground pin current is the regulator quiescent current. the total current drawn from the source is the sum of the load current to the ground current. note 4: thermal regulation is defined as the change in the output voltage at a time t after a change in power dissipation is ap plied, excluding load or line regulation effects. note 5: maximum positive supply voltage of 20v must be of limited duration (<100ms) and duty cycle (<1%). the maximum continuou s supply voltage is 16v. at v in =v out + 1v and i out = 10 ma, c in = 6.8 f, c out = 10 f; t a = 25 c, unless otherwise specified. the boldface applies over the junction temperature range. adjustable versions are set at 5.0v. parameter conditions typ min max units 1.8v version output voltage i out = 10ma 1.8 1.746 1.854 v 10ma i out 1a, 6v v in 16v 1.8 1.710 1.890 2.5v version output voltage i out = 10ma 2.5 2.425 2.575 v 10ma i out 1a, 6v v in 16v 2.5 2.375 2.625 3.3v version output voltage i out = 10ma 3.3 3.201 3.399 v 10ma i out 1a, 6v v in 16v 3.3 3.135 3.465 5.0v version output voltage i out = 10ma 5.0 4.850 5.150 v 10ma i out 1a, 6v v in 16v 5.0 4.750 5.250 all voltage options line regulation i o =10ma, (v out +1v) v in 16v 0.2 1.0 % load regulation v in =v out +1v, 10ma i out 1a 0.3 1.5 % ? v output voltage 20 100 ppm/ c ? t temperature coef. dropout voltage ( note 1) i o =100ma 70 200 mv (except 1.8v version) i o =1a 280 550 ground current (note 3) i o =750ma, v in =v out , + 1v 12 25 ma i o =1a 18 i gnddo ground pin v in =0.1v less than specified v out 1.2 ma current at dropout i out = 10ma current limit v out =0v (note 2) 2.2 1.5 a output noise voltage c l = 10 f 400 v rms 10hz to 100khz) i l =100ma c l =33 f 260 thermal resistance to-220 junction to case, at tab 3 to-220 junction to ambient 60 c/w to-263 junction to case, at tab 3 to-263 junction to ambient 60 electrical characteristics
3 date: 5/27/04 spx2940 1a low dropout voltage regulator ?copyright 2004 sip ex corporation figure 2. line regulation figure 3. load regulation figure 4. ground current vs load current figure 5. ground current vs input voltage reference thermal shutdown in out gnd o.v i limit 28v r1 r2 1.240v + - ibias block diagram 3.320 3.315 3.310 3.305 3.300 3.295 3.290 3.285 3.280 46810121416 v in (v) v out (v) 3.3v device il = 10ma cl = 10 f 3.310 3.305 3.300 3.295 3.290 3.285 3.280 il (a) v out (v) 0.00 0.25 0.50 0.75 1.00 1.25 1.50 3.3v device v in = 4.3v cl = 10 f 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 il (a) ignd (ma) 0.00 0.25 0.50 0.75 1.00 1.25 1.50 3.3v device v in = 4.3v cl = 10 f 300 280 260 240 220 200 180 46 810121416 v in (v) ignd (ma) 3.3v device il = 10ma cl = 10 f typical performance characteristics
4 date: 5/27/04 spx2940 1a low dropout voltage regulator ?copyright 2004 sip ex corporation figure 6. ground current vs current in dropout figure 7. dropout voltage vs load current figure 8. ground current vs temperature at figure 9. output voltage vs temperature at i load = 10ma i load =10ma 100 90 80 70 60 50 40 30 20 10 0 il (a) ignd (ma) 0.00 0.25 0.50 0.75 1.00 1.25 1.50 3.3v device v in = 3.2v cl = 10 f 600 500 400 300 200 100 0 il (a) v dropout (mv) 0.00 0.25 0.50 0.75 1.00 1.25 1.50 3.3v device cl = 10 f 280 270 260 250 240 230 220 210 200 190 180 -40 -20 0 20 40 60 80 t emperature ( c) ignd ( a) 3.3v device v in = 4.3v il = 10ma cl = 10 f 120 100 3.320 3.310 3.300 3.290 3.280 3.270 3.260 3.250 3.240 3.230 3.220 -40 -20 0 20 40 60 80 t emperature ( c) v out (v) 3.3v device v in = 4.3v il = 10ma cl = 10 f 120 100 7.00 6.80 6.60 6.40 6.20 6.00 5.80 5.60 5.40 5.20 5.00 -40 -20 0 20 40 60 80 t emperature ( c) ignd (ma) 3.3v device v in = 4.3v il = 500ma cl = 10 f 120 100 figure 10. ground current vs temperature at figure 11. ground current vs temperature in dropout i load =500ma at i load =750ma 30 29 28 27 26 25 24 23 22 21 20 -40 -20 0 20 40 60 80 t emperature ( c) ignd (ma) 3.3v device v in = 3.2v il = 750ma cl = 10 f 120 100 typical performance characteristics
5 date: 5/27/04 spx2940 1a low dropout voltage regulator ?copyright 2004 sip ex corporation 52.0 50.0 48.0 46.0 44.0 42.0 40.0 38.0 36.0 -40 -20 0 20 40 60 80 t emperature ( c) ignd (ma) 3.3v device v in = 4.3v il = 1.5a cl = 10 f 120 100 figure 12. ground current vs temperature at i load = 1.5a figure 13. ground current vs temperature in dropout at i load =1.5a 100 95 90 85 80 75 70 -40 -20 0 20 40 60 80 t emperature ( c) ignd (ma) 3.3v device v in = 3.2v il = 1.5a cl = 10 f 120 100 350 330 310 290 270 250 230 210 190 170 150 -40 -20 0 20 40 60 80 t emperature ( c) v dropout (mv) 120 100 3.3v device il = 750ma cl = 10 f figure 14. dropout voltage vs temperature at i load = 750ma 500 480 460 440 420 400 380 360 340 320 -40 -20 0 20 40 60 80 t emperature ( c) v dropout (mv) 120 100 3.3v device il = 750a cl = 10 f figure 15. dropout voltage vs temperature at i load = 1.5ma 35 30 25 20 15 10 5 0 -40 -20 0 20 40 60 80 t emperature ( c) i en ( a) 120 100 3.3v device v in = 3.2v il = 750ma cl = 10 f figure 16. enable current vs temperature for v en = 16v 2.00 1.90 1.80 1.70 1.60 1.50 1.40 1.30 1.20 1.10 1.00 -40 -20 0 20 40 60 80 t emperature ( c) v th (v) 120 100 3.3v device v in = 3.2v il = 750ma cl = 10 f figure 17. enable threshold vs temperature typical performance characteristics
6 date: 5/27/04 spx2940 1a low dropout voltage regulator ?copyright 2004 sip ex corporation the spx2940 incorporates protection against over-current faults, reversed load insertion, over temperature operation, and positive and nega- tive transient voltage. thermal considerations although the spx2940 offers limiting circuitry for overload conditions, it is still necessary to insure that the maximum junction temperature is not exceeded in the application. heat will flow through the lowest resistance path, the junction-to-case path. in order to insure the best thermal flow of the component, proper mount- ing is required. consult heatsink manufacturer for thermal resistance and design of heatsink. for example, to-220 design: assume that v in = 10v, v out = 5v, i out = 1.5a, t a = 50 c/w, ha = 1 c/w, ch = 2 c/w, and jc = 3 c/w. where ta = ambient temperature ha = heatsink to ambient thermal resistance ch = case to heatsink thermal resistance jc = junction to case thermal resistance the power calculated under these conditions is: p d = (v in - v out ) * i out = 7.5w. and the junction temperature is calculated as t j = t a + p d * ( ha + ch + jc ) or t j = 50 + 7.5 * (1 + 2 + 3) = 95 c reliable operation is insured. capacitor requirements the output capacitor is needed to insure stability and minimize the output noise. the value of the capacitor varies with the load. however, a minimum value of 10 f aluminum capacitor will guarantee stability over all load conditions. a tantalum capacitor is recommended if a faster load transient response is needed. if the power source has a high ac impedance, a 0.1 f ceramic capacitor between input & ground is recommended. minimum load current to ensure a proper behavior of the regulator under light load, a minimum load of 5ma for spx2940 is required. spx2940 v out v in + 6.8 f + 10 f 1 2 3 figure 18. fixed output linear regulator. application information
7 date: 5/27/04 spx2940 1a low dropout voltage regulator ?copyright 2004 sip ex corporation package: 3 pin to-263 e d l1 b2 e b .160 - .190 .000 - .010 dimensions in inches 3-pin to-263 jedec to-263 (aa) variation .020 - .039 .015 - .029 .070 - .110 - - - a a1 b c d e e1 l l1 l2 min nom max e .100 bsc .066 - .330 - .380 d1 .270 - - .380 - .420 .245 - - h .575 - .625 .070 l3 .010 bsc 123 c c2 a h seating plane l 0?8 see view c e/2 v iew c gauge plane a1 seating plane c with plating base metal b section b-b b b 3 pin to-263
8 date: 5/27/04 spx2940 1a low dropout voltage regulator ?copyright 2004 sip ex corporation h1 b seating plane a1 a chamfer optional c a2 a a e ? q d d1 e2 e/2 l l1 c c d d b c with plating base metal b contact area 1 e e1 .140 - .190 .020 - .055 dimensions in (mm) 3 pin to-220 jedec to-220 (ab) variation .080 - .115 .015 .027 .040 .045 - .070 .480 - .507 a a1 a2 b b2 d1 d2 .380 - .420 e min nom max c .014 - .024 d .560 - .650 .330 - .355 e1 .270 - .350 e2 - - .030 e .100 bsc e1 .200 bsc h1 .230 - .270 l1 - - .250 l2 - - - ? p .139 - .161 q .100 - .135 3 pin to-220 package: 3 pin to-220
9 date: 5/27/04 spx2940 1a low dropout voltage regulator ?copyright 2004 sip ex corporation part number acc. output voltage package spx2940u-1.8 3% 1.8v 3 lead to-220 spx2940u-2.5 3% 2.5v 3 lead to-220 spx2940u-3.3 3% 3.3v 3 lead to-220 spx2940u-5.0 3% 5.0v 3 lead to-220 spx2940t-1.8 3% 1.8v 3 lead to-263 spx2940t-1.8/tr 3% 1.8v 3 lead to-263 spx2940t-2.5 3% 2.5v 3 lead to-263 spx2940t-2.5/tr 3% 2.5v 3 lead to-263 spx2940t-3.3 3% 3.3v 3 lead to-263 spx2940t-3.3/tr 3% 3.3v 3 lead to-263 spx2940t-5.0 3% 5.0v 3 lead to-263 spx2940t-5.0/tr 3% 5.0v 3 lead to-263 corporation analog excellence sipex corporation reserves the right to make changes to any products described herein. sipex does not assume any liability aris ing out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor t he rights of others. sipex corporation headquarters and sales office 233 south hillview drive milpitas, ca 95035 tel: (408) 934-7500 fax: (408) 935-7600 ordering information t o-263-3 package (t) v out gnd v in f ront view t ab = gnd 123 f ront view t ab = gnd to -220-3 package (u) v in v out gnd 3 2 1 package pinouts available in lead free packaging. to order add "-l" suffix to part number. example: spx2940t-3.3/tr = standard; spx2940t-l-3.3/tr = lead free /tr = tape and reel pack quantity is 500 for to-263.
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