rev. 10/11/00 as2715 1.5a high current low dropout voltage regulator adjustable & fixed output, fast response (advanced information) features applications ? adjustable output down to 1.2v ? powering vga & sound card ? 1% output accuracy @ 2.5v, 3.3v& 5.0v ? lcd monitors ? output current of 1.5a ? usb power supply ? low dropout voltage of 350mv @ 1.5a ? power pc ? supplies ? extremely tight load and line regulation ? smps post-regulator ? extremely fast transient response ? high efficiency ?green? computer systems ? reverse-battery and ?load dump? protection ? high efficiency linear power supplies ? standard 3-terminal low cost to-220, to-263 ? portable instrumentation ? constant current regulators ? adjustable power supplies ? battery charger product description the as2715 is a 1.5a high accuracy, low dropout voltage regulator with only 350mv(typ.)@ 1.5a). the as2715 is designed for low voltage application that requires lower dropout voltage and faster transient response. this device is an excellent choice for use in powering low voltage microprocessor that require a lower dropout, faster transient response to regulate from +2.5v to 3.8v supp lies and as a post regulator for switching supplies applications. the as2715 offers full protection against over-current faults, reversed input polarity, reversed load insertion, and positive a nd negative transient voltage. on-chip trimming adjusts the reference voltage to 1%. features such as enable pin, error flag pin are also included in the 5 pin packages. the as2715 is offered in a 3 & 5-pin to-220 & to-263 package compatible with other 3 terminal regulators. for a 3a low dropout regulator refer to the as2730 data sheet. ordering information to-220 3-pin to-263 3-pin as2715u-x as2715t-x x = output voltage (2.5v, 3.3v, 5.0v or blank for adjustable.) consult with factory for other fixed output voltages. pin connections to-263-3 package v out gnd v in as2715 front view 123 front view to-220-3 package as2715 v in v out gnd
rev. 10/11/00 as2715 absolute maximum ratings lead temperature (soldering, 5 seconds) 260 c input voltage) .. 260 c storage temperature range -65 c +150 c input supply voltage (note 1) (survival) -20v to +60v operating junction temperature range .. -40 c +125 c electrical characteristics at i out = 10ma, t a = 25 c, unless otherwise specified. the boldface applies over the junction temperature range. parameter conditions typ as2715 min max units 2.5v version output voltage i out = 10ma 10ma i out 1.5a, 4.3v v in 16v 2.5 2.5 2.475 2.450 2.525 2.550 v 3.3v version2. output voltage i out = 10ma 10ma i out 1.5a, 4.3v v in 16v 3.3 3.3 3.267 3.234 3.330 3.366 v 5.0v version output voltage i out = 10ma 10ma i out 1.5a, 5.5v v in 16v 5.0 5.0 4.95 4.90 5.05 5.10 v all voltage options line regulation i o = 10ma, (v out + 1v) v in 16v 0.1 0.5 % load regulation v in = v out + 5v, 10ma i out i fullload 0.2 1 % ? v 50 100 ppm/ c ? t output voltage temperature coef. i o = 100ma 90 200 i o = 750ma 280 dropout voltage (note 1) i o = 1.5a 490 690 mv ground current (note 3) i o = 750ma, v in = v out , +1v i o = 1.5a 12 25 25 ma i gnddo ground pin current at dropout v in = 0.1v less than specified v out i out = 10ma 0.9 ma current limit v out = 0v (note 2) 2.2 1.7 a output noise voltage (10hz to 100khz) i l = 100ma c l = 10 f c l = 33 f 400 260 v rms reference voltage 1.240 1.228 1.215 1.252 1.265 v adjust pin bias current 40 80 120 na reference voltage temperature coefficient (note 4) 50 ppm/ c adjust pin bias current temperature coefficient 0.1 na/ c
rev. 10/11/00 as2715 upper threshold voltage device set for 3.3v (note 5) 60 40 25 mv lower threshold voltage device set for 3.3v (note 5) 75 95 140 mv hysteresis device set for 3.3v (note 5) 15 mv notes: note 1: dropout voltage is defined as the input-to output differential when the output voltage drops to 95% of its nominal 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: comparator threshold is expressed in terms of a voltage differential at the adjust terminal below the nominal referenc e voltage measured 6v input. to express these thresholds in terms of output voltage change, multiply the error amplifier gain = v out /v ref = (r1 + r2)/r2. for example, at a programmable output voltage of 5v, the error output is guaranteed to go low when the output drops by 95mvx 5v/ 1.240v = 38mv. threshold remain constant as a percent of v out as v out is varied, with the dropout warning occurring at typically 5% below nominal, 7.7% guaranteed. note 6: v en 0.8v and v in 16v, v out = 0. block diagram reference thermal shutdown en in out adj gnd o.v i limit 28v r1* r2* 1.180v 1.240v + + -- flag
rev. 10/11/00 as2715 application hints the as2715 incorporates protection against over-current faults, reversed load insertion, over temperature operation, and positive and negative transient voltage. however, the use of an output capacitor is required in order to insure the stability and the performances. thermal consideration although the as 2715 offers limiting circuitry for overload conditions, it is necessary not to exceed the maximum junction temperature, and therefore to be careful about thermal resistance. the heat flow will follow the lowest resistance path, which is the junction-to-case thermal resistance. in order to insure the best thermal flow of the component, a proper mounting is required. note that the case of the device is electrically connected to the output. the case has to be electrically isolated, a thermally conductive spacer can be used. however do not forget to consider its contribution to thermal resistance. assuming: v in = 10v, v out = 5v, i out = 1.5a, t a = 50 c/w, heatsink case = 6 c/w, heatsink case = 0.5 c/w, jc = 3 c/w power dissipation under this condition p d = (v in ? v out ) * i out = 7.5w junction temperature t j = t a + p d * ( case ? hs + hs jc ) for the control section t j = 50 + 7.5*(0.5 + 6=3) = 121.25 c 121.25 c < t j (max) for the control & power sections. in both case reliable operation is insured by adequate junction temperature. capacitor requirements the output capacitor is needed for stability and to minimize the output noise. the required value of the capacitor varies with the load. however, a minimum value of 10 f aluminum will guarantee stability over load. a tantalum capacitor is recommended for a fast load transient response. if the power source has high ac impedance, a 0.1 f capacitor between input & ground is recommended. this capacitor should have good characteristics up to 250 khz. minimum load current to ensure a proper behavior of the regulator at light load, a minimum load of 5ma for as2715 is required. as2715 fig.1 basic fixed output regulator v out v in
rev. 10/11/00 as2715 ground current vs. input voltage 140 160 180 200 220 240 260 4 6 8 10121416 vin (v) i gnd (ua) 3.3v device il = 1 0ma cl = 10uf ground current vs. load current 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 0 0.25 0.5 0.75 1 1.25 1.5 il (a) i gnd (ma) 3.3v device vin = 4.3v cl = 10uf ground current vs. load current (in dropout) 0 10 20 30 40 50 60 70 80 90 100 0 0.25 0.5 0.75 1 1.25 1.5 il (a) i gnd (ma) 3.3v device vin = 3.2v cl = 10uf dropout voltage vs. load current 0 100 200 300 400 500 600 0 0.25 0.5 0.75 1 1.25 1.5 il (a) v dropout (mv) 3.3v device vin = 3.2v cl = 10uf line regulation 3.280 3.285 3.290 3.295 3.300 3.305 3.310 3.315 3.320 4 6 8 10 12 14 16 vin (v) vout (v) 3.3v device il = 10 ma cl = 10uf load regulation 3.280 3.285 3.290 3.295 3.300 3.305 3.310 0 0.25 0.5 0.75 1 1.25 1.5 il (a) vout (v) 3.3v device vin = 4.3v cl = 10uf
rev. 10/11/00 as2715 output voltage vs. temperature 3.220 3.230 3.240 3.250 3.260 3.270 3.280 3.290 3.300 3.310 3.320 -40 -20 0 20 40 60 80 100 120 temperature ( o c) vout (v) 3.3v device vin = 4.3v il = 10ma cl = 10uf ground current vs. temperature (il = 500ma) 5.00 5.20 5.40 5.60 5.80 6.00 6.20 6.40 6.60 6.80 7.00 -40 -20 0 20 40 60 80 100 120 temperature ( o c) i gnd (ma) 3.3v device vin = 4.3v il = 500ma cl = 10uf ground current vs. temperature (il = 10ma) 180 190 200 210 220 230 240 250 260 270 280 -40 -20 0 20 40 60 80 100 120 temperature ( o c) i gnd (ua) 3.3v device vin = 4.3v il = 10ma cl = 10uf ground current vs. temperature (il = 1.5a) 36.0 38.0 40.0 42.0 44.0 46.0 48.0 50.0 52.0 -40 -20 0 20 40 60 80 100 120 temperature ( o c) i gnd (ma) 3.3v device vin = 4.3v il = 1.5a cl = 10uf ground current vs. temperature (in dropout, il = 1.5a) 70 75 80 85 90 95 100 -40 -20 0 20 40 60 80 100 120 temperature ( o c) i gnd (ma) 3.3v device vin = 3.2v il = 1.5a cl = 10uf ground current vs. temperature (in dropout, il = 750ma) 25 26 27 28 29 30 31 32 33 34 35 -40 -20 0 20 40 60 80 100 120 temperature ( o c) i gnd (ma) 3.3v device vin = 3.2v il = 750ma cl = 10uf
rev. 10/11/00 as2715 dropout voltage vs. temperature (il = 750ma) 200 220 240 260 280 300 320 340 360 380 400 -40 -20 0 20 40 60 80 100 120 temperature ( o c) v dropout (mv) 3.3v device vin = 3.2v il = 750ma cl = 10uf
rev. 10/11/00 as2715 package drawing to-263-3l (t) 0.103 bsc 0.050 (1.270) 0.600 + - 0.025 0.405 0.005 0.055 (1.397) (10.287 0.127) 0.356 0.005 (9.042 0.127) (15.24 0.635) (2.616) 0.032 + - 0.001 (0.813 0.025) + - 0.176 0.005 0.050 0.002 0.015 + - 0.003 0 8 (0.381 0.074) + - 0.100 0.010 (2.540 0.254) (4.470 0.127) (1.270 0.051)
rev. 10/11/00 as2715 package drawing to-220-3l (u) 0.408 0.013 (10.36 0.33) 0.110 0.010 (2.794 0.254) 0.250 0.010 (6.350 0.254) 0.151d 0.002 (3.835 d 0.051) 0.180 0.005 (4.572 0.127) 0.050 0.002 (1.270 0.051) 0.340 0.010 (8.636 0.254) 0.150 min (3.81 min) 0.410 (10.41) 0.100 0.010 (2.540 0.254) 0.032 0.005 (0.813 0.127) 0.540 0.015 (13.720 0.381) 0.050 typ (1.27 typ) 0.200 0.010 (5.080 0.254) 0.015 0.010/-0.002 (0.381 0.254/-0.051) 0.015 0.010/-0.015 (2.667 0.254/-0.381) 1.020 0.015 (25.910 0.381) seating plane tapered 1 o 2 sides 7 o typ.
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