preliminary t echnical data ADP3089 a rev. pre 8/26/02 information furnished by analog devices is believed to be accurate and reliable. however, no responsibility is assumed by analog devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of analog devices. one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 781/329-4700 world wide web site: ht tp://www.analog.com fax: 781/326-8703 analog devices, inc., 2002 1 mhz, 1 a buck regulator preliminary technical data features 1 mhz pwm frequency ultrasmall 8-lead 3 3 sq. mm chip scale package automatic pwm to power saving mode at light load fully integrated 1.5 a power switch 3% output regulation accuracy over temperature, line, and load 100% duty cycle operation simple compensation output voltage: 1.25 v to 10 v small inductor and mlc capacitors low quiescent current while pulse skipping thermal shutdown fully integrated soft start cycle-by-cycle current limit applicatons pdas and palmtop computers notebook computers pcmcia cards bus products portable instruments industrial systems general description the ADP3089 is a high frequency, non-synchronous pwm step-down dc-dc regulator with an integrated 1.5 a power switch in a space-saving chip scale package. it pro- vides high efficiency, excellent dynamic response, and is very simple to use. the ADP3089?s 1 mhz switching frequency allows for small, inexpensive external components, and the current mode control loop is simple to compensate and eases noise filtering. it operates in pwm current mode under heavy loads and saves energy at lighter loads by switching auto- matically into power saving mode. soft start is integrated completely on chip, as is the cycle-by-cycle current limit. capable of operating from 2.5 v to 11 v input with a typical output current of 1 a, it is ideal for portable, bat- tery powered, industrial, pc and instrumentation applica- tions. supporting output voltages down to 1.25 v, the ADP3089 is ideal to generate low voltage rails, providing the optimal solution in its class for delivering power effi- ciently, responsively, and simply with minimal printed circuit board area. the device is specified over the industrial temperature range of -40c to +85c, and is offered in an ultrasmall 8- lead 3 3 square mm chip scale package. functional block diagram figure 1. typical application sw fb comp gnd in drv current sense amp pwm comparator ref 1.245v error amp g m soft-start timer + r sq run/stop comparators 1mhz protection logic (ilim, ot) in gnd sw gnd fb in gnd comp ADP3089 v out 1.8v@1a 10 h 18.2k ? 41.2k ? 10.7k ? 470pf 20bq030 in drv 22f 0.1f 10f 47pf
?2? rev. pre ADP3089?specifications 1 (v (v (v (v (v in in in in in = +3.3 v, t = +3.3 v, t = +3.3 v, t = +3.3 v, t = +3.3 v, t a a a a a = -40c to +85c, unless otherwise noted) = -40c to +85c, unless otherwise noted) = -40c to +85c, unless otherwise noted) = -40c to +85c, unless otherwise noted) = -40c to +85c, unless otherwise noted) parameter symbol conditions min typ max units supply input voltage range v in drv to gnd 2.5 11 v quiescent current operating i q v in = 10 v, i l = 1 a, 12 ma drv = gnd no load 180 280 a shutdown i sd v comp = 0 v 15 40 a ground current i gnd 2 normal operation v in = 10 v, i l = 1 a, 3 3.6 ma drv = 2 v thermal shutdown threshold t sd 160 c oscillator oscillator frequency f sw 0.75 1 1.25 mhz minimum sleep duty cycle d psm 14 % maximum duty cycle d max 100 % wake up hysteresis v hyst fb voltage drops below v ref 20 30 40 mv output switch switch on voltage v io 3 i l = 1a, fb and drv tied to .7 1.0 v gnd current limit threshold i lim 1.5 1.7 2 a leakage current v in = 12 v 0.5 a error amplifier reference voltage accuracy v ref fb tied to comp 1.222 1.245 1.265 v reference voltage line fb tied to comp, .02 %/v regulation v in = 3 v to 12 v feedback input bias current i fb soft start expired -50 1 50 na maximum output current i comp , sc 35 60 85 a short circuit current i comp , sd v comp = 0 v, activating 20 40 a shutdown transconductance g m , ea v fb to i comp 480 a/v modulator transconductance g m , mod v comp to i l 1a/v control offset voltage v pwm , os 0.90 v soft start time t ss 250 600 s shutdown threshold voltage v comp , sd 340 750 mv slope compensation m sc effectively summed to i sw 0.5 a/s notes 1 all limits at temperature extremes are guaranteed via correlation using standard statistical quality control (sqc). 2 for higher efficiency operation, tie the drv pin to the output for i l < 250 ma, and v in > 3 v. 3 v(in) - v(sw), includes voltage drop across internal current sensor. specifications subject to change without notice. preliminary technical data
ADP3089 ?3? rev. pre ordering guide temperature package branding model range option information ADP3089acp -40c to +85c csp-8 3 3 p7a caution esd (electrostatic discharge) sensitive device. electrostatic charges as high as 4000 v readily accumulate on the human body and test equipment and can discharge without detection. although the device features proprietary esd protection circuitry, permanent damage may oc- cur on devices subjected to high energy electrostatic discharges. therefore, proper esd precautions are recommended to avoid performance degradation or loss of functionality. pin function descriptions pin mnemonic function 1, 2 in power supply input. both pins must be connected. 3, 6 gnd ground. both pins must be con- nected. 4 comp feedb ack loop compensation and shutdown input. an open drain or collector used to pull the pin to ground will shutdown the device. 5 fb feedback voltage sense input. this pin senses the voltage via an external resistor divider. 7 drv this pin provides a separate path for drive current to be con- nected to ground. 8 sw switching output. absolute maximum ratings* input supply voltage .............................. ?0.3 v to +12 v voltage on any pin with respect to gnd ............................................................ ?0.3 v to +12 v (voltage on any pin may not exceed v in ) operating ambient temperature range .. ?40c to +85c operating junction temperature ......................... +125c ja (4-layer board ) ............................................... 47c/w storage temperature range .................. ?65c to +150c lead temperature range (soldering, 10 sec) ..... +240c vapor phase (60 sec) ........................................ +240c infrared (20 sec) ............................................... +240c *this is a stress rating only; operation beyond these limits can cause the device to be permanently damaged. unless otherwise specified, all voltages are referenced to gnd. pin configuration preliminary technical data top view* 1 2 3 45 6 7 8 in in gnd comp sw drv gnd fb * pin?s underside
ADP3089 ?4? rev. pre preliminary technical data outline dimensions dimensions shown in inches and (mm). 12
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