1 of 4 pin configurations general description the rt9178 is designed for portable rf and wireless applications with demanding performance and space requirements. the rt9178 ? s performance is optimized for battery- powered systems to deliver ultra low noise and low quiescent current. a noise bypass pin is also available for further reduction of output noise. regulator ground current increases only slightly in dropout, further prolonging the battery life. the rt9178 also works with low-esr ceramic capacitors, reducing the amount of board space necessary for power applications, critical in hand-held wireless devices. the rt9178 consumes less than 0.01 a in shutdown mode and has fast turn-on time less than 100 s. the other features include ultra low dropout voltage, high output accuracy, current limiting protection, and high ripple rejection ratio. available in the sot-23-5 package. applications cdma/gsm cellular handsets battery-powered equipment laptop, palmtops, notebook computers hand-held instruments pcmcia cards portable information appliances ordering information (top view) marking information for marking information, contact our sales representative directly or through a richtek distributor located in your area, otherwise visit our website for detail. features ultra-low-noise for rf application ultra-fast response in line/load transient quick start-up (typically 100 s) < 0.01 a quiescent current when shutdown low dropout : 200mv at 200ma wide operating voltage ranges : 2.5v to 6.0v ttl-logic-controlled shutdown input low temperature coefficient current limiting protection thermal shutdown protection only 1 f output capacitor required for stability high power supply rejection ratio custom voltage available rohs compliant and 100% lead (pb)-free sot-23-5 vout gnd en bp vin r-type 2 3 5 4 1 sot-23-5 vin gnd bp en vout 2 3 5 4 1 rt9178- package type b : sot-23-5 br : sot-23-5 (r-type) operating temperature range p : pb free with commercial standard g : green (halogen free with commer- cial standard) output voltage 24 : 2.4v 25 : 2.5v : 31 : 3.1v 32 : 3.2v 2h : 2.85v 4008-318-123 sales@twtysemi.com http://www.twtysemi.com rt9178 product specification
function block diagram functional pin description typical application circuit pin no. rt9178- cb rt9178- cbr pin name pin function 1 3 vin power input voltage 5 1 vout output voltage 2 2 gnd ground 3 4 en enable input logic, active low. if the shutdown feature is not required, connect en to vin. 4 5 bp reference noise bypass vin gnd vout rt9178 + + c out 2.2uf c in 1uf v in v out en bp c bp 10nf chip enable current-limit and thermal protection mos driver + - vout shutdown and logic control vin error amplifier v ref bp en gnd quick start rt9178 product specification 2 of 4 4008-318-123 sales@twtysemi.com http://www.twtysemi.com
recommended operating conditions (note 3) supply input v oltage ------------------------------------------------------------------------------------------------- 2. 5v to 6v enable input v oltage ------------------------------------------------------------------------------------------------- 0v to 6v junction temperature range --------------------------------------------------------------------------------------- ? 40 c to 125 c electrical characteristics (v in = v out + 1v, c in =c out = 1 f, c bp = 1nf, t a = 25c unless otherwise specified) absolute maximum ratings (note 1) supply input voltage ------------------------------------------------------------------------------------------------- 7v enable in put voltage ------------------------------------------------------------------------------------------------- 7v power dissipation, p d @ t a = 25 c sot-23-5 --------------------------------------------------------------------------------------------------------------- 0.4w package thermal resistance (note 8) sot-23-5 , ja ---------------------------------------------------------------------------------------------------------- 250 c/w lead temperature (soldering, 10 sec.) -------------------------------------------------------------------------- 260 c junction te mperature ------------------------------------------------------------------------------------------------ 150 c storage temperature range ---------------------------------------------------------------------------------------- ? 65 c to 150 c esd susceptibility (note 2) hbm (human body mode) ----------------------------------------------------------------------------------------- 2kv mm (m achine mode) ------------------------------------------------------------------------------------------------- 200v parameter symbol test conditions min typ max units output voltage accuracy v out i out = 1ma ? 2 -- +2 % current limit i lim r load = 1 -- 400 -- ma quiescent current (note 6) i q v en > 1.0v, i out = 0ma -- 90 150 a dropout voltage (note 4) v drop i out = 200ma -- 200 300 mv line regulation v line v in = (v out + 0.3v) to 6.0v, i out = 1ma -- -- 6 mv/v load regulation (note 5) v load 1ma < i out < 200ma -- 7 20 mv standby current (note 7) i stby v en = gnd, shutdown -- 0.01 1 a en input bias current i ibsd v en = gnd or vin -- 0 100 na logic-low voltage v il v in = 3v to 5.5v, shutdown -- -- 0.4 en threshold logic-high voltage v ih v in = 3v to 5.5v, start-up 1.0 -- -- v output noise voltage e no 10hz to 100khz, i out = 200ma c out = 10 f -- 50 -- v rms f = 100hz -- ? 70 -- power supply rejection rate f = 10khz psrr c out = 10 f, i out = 200ma -- ? 40 -- db thermal shutdown temperature t sd -- 150 -- c rt9178 product specification 3 of 4 4008-318-123 sales@twtysemi.com http://www.twtysemi.com
note 1. stresses listed as the above "absolute maximum ratings" may cause permanent damage to the device. these are for stress ratings. functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. note 2. devices are esd sensitive. handling precaution recommended. note 3. the device is not guaranteed to function outside its operating conditions. note 4. the dropout voltage is defined as v in -v out , which is measured when v out is v out(normal) ? 100mv. note 5. regulation is measured at constant junction temperature by using a 20ms current pulse. devices are tested for load regulation in the load range from 1ma to 200ma. note 6. quiescent, or ground current, is the difference between input and output currents. it is defined by i q = i in - i out under no load condition (i out = 0ma). the total current drawn from the supply is the sum of the load current plus the ground pin current. note 7. standby current is the input current drawn by a regulator when the output voltage is disabled by a shutdown signal (v en = gnd). it is measured with v in = 6v. note 8. ja is measured in the natural convection at t a = 25 c on a low effective thermal conductivity test board of jedec 51-3 thermal measurement standard. rt9178 product specification 4 of 4 4008-318-123 sales@twtysemi.com http://www.twtysemi.com
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