rev. 10/17/00 as2730/31/32/33 3a 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 @ 3.3v, 5.0v ? power pc ? supplies ? output current of 3a ? smps post-regulator ? low dropout voltage 370mv(typ.) @ 3a. ? high efficiency ?green? computer systems ? extremely tight load and line regulation ? high efficiency linear power supplies ? extremely fast transient response ? portable instrumentation ? standard 3-terminal low cost to-220, to-263 ? constant current regulators ? reverse-battery and ?load dump? protection ? adjustable power supplies ? zero current shutdown mode (5-pin versions) ? battery charger ? error flag signal output out-of regulation (5-pin versions) product description the as2730/31/32/33 is a 3a high accuracy, low dropout voltage regulator (370mv(typ)@ 3a). the as2730/31/32/33 is designed for low voltage application that requires lower dropout voltage and faster transient response. this device is an excellent cho ice for use in powering low voltage microprocessor that require a lower dropout, faster transient response to regulate from +2.5v to 3.8v s upplies and as a post regulator for switching supplies applications. the as2730/31/32/33 offers full protection against over-current faults, reversed input polarity, reversed load insertion, and p ositive and 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 package. the as2730/31/32/33 are offered in 3 & 5 pin to-220 & to-263 packages compatible with other 3 terminal regulators. for a 5a low dropout regulator refer to the as2750 datasheet. ordering information to-220 3-pin to-263 3-pin as2730/31/32/33u-x as2730/31/32/33t5-x x = output voltage (x = 3.0v, 5.0v, or blank for adj (5-pin devices only) consult with factory for other fixed output voltages. pin connections top view to-263-3 (t) 1 alpha as2730 2 3 to-263-5 (t) top view 45 alpha as2731/32/33 12 3 front view to-220-3 (u) alpha as2730 1 23 to-220-5 (u) front view 5 4 3 2 1 alpha as2731/32/33 as2731 AS2732 as2733 1) enable 2) input 3) gnd 4) output 5) flag 1) enable 2) input 3) gnd 4) output 5) adjust 1) flag 2) input 3) gnd 4) output 5) adjust as2731 AS2732 as2733 1) enable 2) input 3) gnd 4) output 5) flag 1) enable 2) input 3) gnd 4) output 5) adjust 1) flag 2) input 3) gnd 4) outpu t 5) adjust
rev. 10/17/00 as2730/31/32/33 absolute maximum ratings lead temp. (soldering, 5 seconds) ................................ 260c maximum input voltage .................................. .... 16v storage temperature range ...................................................... -65 to +150c operating junction temperature range as2730/31/32/33 control section .................................. -45c +125c as2730/31/32/33 power transistor................................. -45c +150c electrical characteristics (note 1) at i out = 10ma, t a =25 c, unless otherwise specified. parameter conditions typ as2730/31/32/33 min max units 3.3v version output voltage (note 2) i out = 10ma 10ma i out 3a, 4.75v v in 16v 3.3 3.3 3.270 3.240 3.330 3.360 v 5.0v version output voltage (note 2) i out = 10ma 10ma i out 3a, 5.5v v in 16v 5.0 5.0 4.95 4.90 5.05 5.10 v all voltage options reference voltage 1.240 1.228 1.215 1.252 1.265 v reference voltage (note 8)` 1.203 1.277 v line regulation i o = 10ma, (v out + 1v) v in 16v 0.06 0.5 % load regulation v in = v out + 5v, 10ma i out i fullload (note 2, 6) 0.2 1 % ? v 20 100 ppm/ c ? t output voltage (note 6) temperature coef. i o = 100ma 80 175 i o = 1.5a 250 dropout voltage i o = 3a 370 600 mv ground current i o = 1.5a, v in = v out , +1v i o = 3a 10 37 35 ma i gnddo ground pin current at dropout v in = 0.5v less than specified v out i out = 10ma 0.9 ma current limit v out = 0v (note 4) 4.5 3.0 a output noise voltage (10hz to 100khz) i l = 100ma c l = 10 f c l = 33 f 400 260 v rms adjust pin bias current 40 80 120 na reference voltage temperature coefficient (note 7) 20 ppm/ c adjust pin bias current temperature coefficient 0.1 na/ c flag output (error comparator) as2731/as2733 output leakage current v oh = 16v 0.01 1.00 2.00 a output low voltage device set for 5v. v in = 4.5v i ol = 250 a 220 300 400 mv
rev. 10/17/00 as2730/31/32/33 (cont.) upper threshold voltage device set for 5v (note 9) 60 40 25 mv lower threshold voltage device set for 5v (note 9) 75 95 140 mv hysteresis device set for 5v (note 9) 15 mv enable input as 2731/AS2732 input logic voltage low (off) high (on) 2.4 0.8 v v en = 16v 100 600 750 v enable pin input current v en = 0.8v 1 2 a regulator output current in shutdown (note 10) 10 500 a notes: the bold specifications apply to the full operating temperature range. note 1: maximum positive supply voltage of 60v must be of limited duration (<100msec) and duty cycle.) the maximum continuous supply voltage is 16v. note 2: full load current (i fl ) is defined as 1.5a for the note 3: dropout voltage is defined as the input-to output differential when the output voltage drops to 99% of its nominal val ue with v out + 1v applied to v in . note 4: v in = v out (nominal) +1v. for example, use v in = 4.3v for a3.3v regulator. employ pulse-testing procedures to minimize temperature rise. note 5: 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 6: output voltage temperature coefficient is defined as the worst case voltage changed divided by the total temperature r ange. note 7: thermal regulation is defined as the change in the output voltage at a time t after a change in power dissipation is a pplied, excluding load or line regulation effects. specifications are for a 200ma load pulse as v in = 20v (a 4w pulse) for t = 10ms. note 8: v ref v out (v in ? 1), 2.3v v in 16v, 10ma < il i fl , tj t jmax note 9: comparator threshold is expressed in terms of a voltage differential at the adjust terminal below the nominal referenc e voltage measured a 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 con stant 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 10: v en 0.8v and v in 16v, v out = 0.
rev. 10/17/00 as2730/31/32/33 application hints the as2730/31/32/33 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 2730/31/32/33 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 10ma for as2730/31/32/33 is required. adjustable regulator design as2730/31are adjustable regulators and maybe programmed for any value between 1.25v and 16v using two resistors. the relation between the resistors is given by: r 1 =r 2 (v out /1.240 ?1) resistors have a large value up to 1m ? in order to reduce the current consumption. this might be interesting in the case of widely varying load currents. error flag as2731/33 features an error indicating either an over current fault or a low input voltage. this flag pulls low when such a problem occurs and may sink 10ma. it is inoperative during thermal shutdown. enable input as2731/32 features enable input allowing turning on & off the device. en has been designed to be compatible with ttl/cmos logic. when the regulator is on, the current flowing through this pin is approximately 20 a. as2730 fig.1 basic fixed output regulator v out v in AS2732/33 fig. 2 adjustable output voltage regulator v out v in 1 2 3 4 5 r 2 r 1 for best results, the total series resistance should be small enough to pass the minimum regulator load current v out = v ref x [ 1 + (r 1 /r 2 ) ]
rev. 10//17/00 as2730/31/32/33 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. 10/17/00 as2730/31/32/33 package drawing to-263-5l (t) 0.405 0.005 0.055 (1.397) 0.356 0.005 (10.287 0.127) (9.042 0.127) (15.24 0.635) 0.600 0.025 (1.702 0.127) 0.067 0.005 (0.813 0.076) 0.032 0.003 0.176 0.005 (4.470 0.127) 0.050 0.002 (1.270 0.051) 0.015 + - 0.003 0 8 (0.381 0.074) + - 0.100 0.010 (2.540 0.254)
rev. 10/17/00 as2730/31/32/33 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.
rev. 10/17/00 as2730/31/32/33 package drawing to-220-5l (u) 0.108 + - 0.005 (2.74 + - 2.74) 0.400 + - 0.005 (10.16 + - 0.13) 0.150 d + - 0.005 (3.81d + - 0.13) 0.175 + - 0.005 (4.45 + - 0.13) 0.050 + - 0.005 (1.27 + - 0.13) 0.250 + - 0.005 (6.35 + - 0.13) 0.590 + - 0.005 (14.99 + - 0.13) seating plane 0.547 + - 0.005 (13.89 + - 0.005) 0.067 + - 0.005 (1.70 + - 0.127) 0.268 ref (6.81 ref) 0.268 ref 0.032 + - 0.005 (0.81 + - 0.13) 0.015 + - 0.005 (0.38 + - 0.13) 0.105 + - 0.005 (2.67 + - 0.13) 1.137 ref (28.88 ref) 7 typ.
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