? 2000 semtech corp. 652 mitchell road newbury park ca 91320 very low dropout 1.5 amp regulator with enable sc1565 october 3, 2000 1 volts r2 r2) (r1 1.200 vo + = features ? = 350mv dropout @ 1.5a ? = adjustable output from 1.2v to 4.8v (1) ? = 2.5v and 1.8v options (adjustable externally using resistors) (1) ? = over current and over temperature protection ? = enable pin (1) ? = 10a quiescent current in shutdown (1) ? = low reverse leakage (output to input) ? = surface mount and through-hole packages ? = full industrial temperature range note: (1) so-8 and to-220-5l packages only. description the sc1565 is a high performance positive voltage regulator designed for use in applications requiring very low dropout voltage at up to 1.5 amps. since it has superior dropout characteristics compared to regular ldos, it can be used to supply 2.5v on motherboards or 2.8v on peripheral cards from the 3.3v supply thus allowing the elimination of costly heatsinks. additionally, the 5-lead to-220 and so-8 versions have an enable pin to further reduce power dissipation while shut down. the sc1565 provides excellent regulation over variations in line, load and temperature. the sc1565 is available in the popular so-8 surface mount package with two internally preset output voltage options, which are also adjustable using external resistors. also available are 5-lead and 3-lead to-220 2.5v options (fixed output only for the 3-lead option) and fixed output sot-223 options. applications ? = battery powered systems ? = motherboards ? = peripheral cards ? = pcmcia cards tel:805-498-2111 fax:805-498-3804 web:http:// www.semtech.com ordering information notes: (1) where -x.x denotes voltage options. available voltages are: 2.5v and 1.8v. output voltage can be ad- justed (except sot-223 and to-220-3) using external resistors, see pin description. (2) only available in tape and reel packaging. a reel contains 2500 devices. (3) only available in tube packaging (no suffix re- quired). device (1) package sc1565is-x.x.tr (2) so-8 sc1565ist-x.x.tr (2) sot-223 sc1565it-x.x (3) to-220-3 sc1565i5t-x.x (3) to-220-5 typical applications vin vo enable u1 sc1565is-x.x 1 2 3 4 5 6 7 8 en vin vo adj gnd gnd gnd gnd c1 c2 r1 r2 vin vo enable u1 sc1565is-x.x 1 2 3 4 5 6 7 8 en vin vo adj gnd gnd gnd gnd c1 c2 vin vo c2 c1 u1 sc1565it-2.5v and sc1565ist-x.x 1 2 3 vin gnd vo vin enable vo c1 c2 r1 r2 u1 sc1565i5t-2.5 2 1 3 5 4 vin en gnd adj vo notes: (1) maximum vo setpoint for 1.8v parts = 5.4v. (2) this device is designed to operate with ceramic input and output capacitors. volts r2 r2) (r1 1.200 vo + =
? 2000 semtech corp. 652 mitchell road newbury park ca 91320 very low dropout 1.5 amp regulator with enable sc1565 october 3, 2000 2 absolute maximum ratings parameter symbol max units input voltage v in 5.5 v power dissipation p d internally limited w thermal resistance junction to ambient so-8 (1) sot-223 to-220-x ja 65 63 50 c/w thermal resistance junction to case so-8 sot-223 to-220-x jc 39 27 3 c/w operating ambient temperature range t a -40 to 85 c operating junction temperature range t j -40 to 150 c storage temperature range t stg -65 to 150 c lead temperature (soldering) 10 sec. t lead 300 c esd rating (human body model) esd 4 kv note: (1) 1 square inch of fr-4, double sided, 1 oz. minimum copper weight. electrical characteristics unless specified: v en = v in adjustable option (v adj > v th(adj) ): v in = 2.2 to 5.5v and i o = 10a to 1.5a fixed options (v adj = gnd): v in = (v o + 0.7v) to 5.5v and i o = 0a to 1.5a values in bold apply over the full operating temperature range. parameter symbol test conditions min typ max units vin supply voltage range vin 2.2 5.5 v quiescent current i q v in = 3.3v 0.75 1.75 ma v in = 5.5v, v en = 0v 10 35 a vo output voltage (1) v o v in = v o + 0.7v, i o = 10ma 0.99v o v o 1.01v o v (internal fixed voltage) 0.98v o v o 1.02v o line regulation (1) reg (line) v in = (v o + 0.25v) to 5.5v, i out = 10ma 0.035 0.3 % load regulation (1) reg (load) v in = v o + 0.7v 0.2 0.4 %
? 2000 semtech corp. 652 mitchell road newbury park ca 91320 very low dropout 1.5 amp regulator with enable sc1565 october 3, 2000 3 electrical characteristics unless specified: v en = v in adjustable option (v adj > v th(adj) ): v in = 2.2 to 5.5v and i o = 10a to 1.5a fixed options (v adj = gnd): v in = (v o + 0.7v) to 5.5v and i o = 0a to 1.5a values in bold apply over the full operating temperature range. parameter symbol test conditions min typ max units dropout voltage (2) v d i load = 10ma 2.5 10 mv 20 i load = 500ma 115 300 mv 400 i load = 1a 225 400 mv 500 i load = 1.5a 350 500 mv 600 minimum load current (3) i o v in = v o + 0.7v 1 10 a current limit i cl 1.50 2.50 3.50 a adj reference voltage (1) v ref v in = 2.2v, v adj = v out , i o = 10ma 1.188 1.200 1.212 v 1.176 1.224 adjust pin current (4) i adj v adj = v ref 10 50 na adjust pin threshold (5) v th(adj) 0.10 0.20 0.40 v en enable pin current i en v en = 0v, v in = 3.3v 1.5 10 a enable pin threshold v ih v in = 3.3v 1.8 v v il v in = 3.3v 0.4 over temperature protection high trip level t hi 170 c hysteresis t hyst 20 c notes: (1) low duty cycle pulse testing with kelvin connections required. (2) defined as the input to output differential at which the output voltage drops to 1% below the value measured at a differential of 0.7v. (3) required to maintain regulation. voltage set resistors r1 and r2 are usually utilized to meet this requirement. adjustable versions only. (4) guaranteed by design. (5) when v adj exceeds this threshold, the ?sense select? switch disconnects the internal feedback chain from the error amplifier and connects v adj instead.
? 2000 semtech corp. 652 mitchell road newbury park ca 91320 very low dropout 1.5 amp regulator with enable sc1565 october 3, 2000 4 pin descriptions pin name pin functiom adj this pin, when grounded, sets the output voltage to that set by the internal feedback resistors. if ex- ternal feedback resistors are used, the output voltage will be (see application circuit): en enable input. pulling this pin below 0.4v turns the regulator off, reducing the quiescent current to a fraction of its operating value. the device will be enabled if this pin is left open. connect to vin if not being used. gnd reference ground. use all four pins on the so-8 device for heatsinking. use the tab on the to-220 devices for heatsinking. vin input voltage. for regulation at full load, the input to this pin must be between (vo + 0.7v) and 5.5v. minimum vin = 2.2v. vo this pin is the power output of the device. volts r2 r2) (r1 1.200 vo + = * * block diagram * not on 3-lead to-220
? 2000 semtech corp. 652 mitchell road newbury park ca 91320 very low dropout 1.5 amp regulator with enable sc1565 october 3, 2000 5 pin configurations so-8 top view sc1565 3-pin versions pin function 1vin 2gnd 3vo tab is ground to-220-3 sc1565 5-pin versions pin function 1en 2vin 3gnd 4vo 5adj tab is ground to-220-5 pin function 1vin 2gnd 3vo tab is ground sot-223
? 2000 semtech corp. 652 mitchell road newbury park ca 91320 very low dropout 1.5 amp regulator with enable sc1565 october 3, 2000 6 2.450 2.460 2.470 2.480 2.490 2.500 2.510 2.520 2.530 2.540 2.550 -50 -25 0 25 50 75 100 125 150 t j (c) v o (v) vin = 5.5v i o = 10ma i o = 1.5a typical characteristics output voltage (2.5v) vs. junction temperature vs. output current 0 100 200 300 400 500 600 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 i o (a) v d (mv) -40c 0c 25c 150c dropout voltage vs. output current vs. junction temperature 0 100 200 300 400 500 600 -50 -25 0 25 50 75 100 125 150 t j (c) v d (mv) i o = 1.0a i o = 0.5a i o = 1.5a dropout voltage vs. junction temperature vs. output current 2.450 2.460 2.470 2.480 2.490 2.500 2.510 2.520 2.530 2.540 2.550 -50 -25 0 25 50 75 100 125 150 t j (c) v o (v) vin = 3.2v i o = 10ma i o = 1.5a output voltage (2.5v) vs. junction temperature vs. output current 1.175 1.180 1.185 1.190 1.195 1.200 1.205 1.210 1.215 1.220 1.225 -50 -25 0 25 50 75 100 125 150 t j (c) v ref (v) vin = 2.2v i o = 10ma i o = 1.5a reference voltage vs. junction temperature vs. output current 1.175 1.180 1.185 1.190 1.195 1.200 1.205 1.210 1.215 1.220 1.225 -50 -25 0 25 50 75 100 125 150 t j (c) v ref (v) vin = 5.5v i o = 1.5a i o = 10ma reference voltage vs. junction temperature vs. output current
? 2000 semtech corp. 652 mitchell road newbury park ca 91320 very low dropout 1.5 amp regulator with enable sc1565 october 3, 2000 7 typical characteristics (cont.) 0 1 2 3 4 5 6 7 8 9 10 -50 -25 0 25 50 75 100 125 150 t j (c) i q(off) (a) vin = 5.5v off-state quiescent current vs. junction temperature 500 510 520 530 540 550 560 570 580 590 600 -50 -25 0 25 50 75 100 125 150 t j (c) i q (a) vin = 3.3v quiescent current vs. junction temperature applications information introduction the sc1565 is intended for applications such as graphics cards where high current capability and very low dropout voltage are required. it provides a very simple, low cost solution that uses very little pcb real estate. additional features include an enable pin to al- low for a very low power consumption standby mode, and a fully adjustable output. component selection input capacitor - a 4.7f ceramic capacitor is recom- mended. this allows for the device being some dis- tance from any bulk capacitance on the rail. addition- ally, input droop due to load transients is reduced, im- proving load transient response. additional capaci- tance may be added if required by the application. output capacitor - a minimum bulk capacitance of 10f, along with a 0.1f ceramic decoupling capacitor is recommended. increasing the bulk capacitance will improve the overall transient response. the use of multiple lower value ceramic capacitors in parallel to achieve the desired bulk capacitance will not cause stability issues. although designed for use with ce- ramic output capacitors, the sc1565 is extremely toler- ant of output capacitor esr values and thus will also work comfortably with tantalum output capacitors. external voltage selection resistors - the use of 1% re- sistors, and designing for a current flow 10a is rec- ommended to ensure a well regulated output (thus r2 120k ? ). thermal considerations the power dissipation in the sc1565 is approximately equal to the product of the output current and the input to output voltage differential: the absolute worst-case dissipation is given by: for a typical scenario, vin = 3.3v 5%, vout = 2.8v and i o = 1.5a, therefore: vin (max) = 3.465v, vout (min) = 2.744v and i q(max) = 1.75ma, thus p d(max) = 1.09w. using this figure, and assuming t a(max) = 70c, we can calculate the maximum thermal impedance allowable to maintain t j 150c: this should be achievable for the so-8 package using pcb copper area to aid in conducting the heat away, such as one square inch of copper connected to the ground pins of the device. the sot-223 and to-220 packages would not require heatsinking. internal ground/power planes and air flow will also assist in re- moving heat. for higher ambient temperatures it may be necessary to use additional copper area. () o d i vout vin p ? ? ( ) ) max ( q ) max ( ) max ( o ) min ( ) max ( ) max ( d i vin i vout vin p ? + ? ? = () () r tt p cw th j a max jmax a max dmax ()( ) () () () . ./ ? = ? = ? = 150 70 109 73 4
? 2000 semtech corp. 652 mitchell road newbury park ca 91320 very low dropout 1.5 amp regulator with enable sc1565 october 3, 2000 8 outline drawing - so-8 jedec ref: ms-012aa land pattern - so-8
? 2000 semtech corp. 652 mitchell road newbury park ca 91320 very low dropout 1.5 amp regulator with enable sc1565 october 3, 2000 9 land pattern sot-223 device outline sot-223
? 2000 semtech corp. 652 mitchell road newbury park ca 91320 very low dropout 1.5 amp regulator with enable sc1565 october 3, 2000 10 device outline - to-220-3l device outline - to-220-5l ecn00-1357
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