2012/11/15 v. 1 page 1 SP3406 600ma buck converter description applications SP3406 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. the device is available in an adjustable version and fixed output voltages, such as 1.5v,1.8v,etc. supply current with no load is 30ua and drops to <1ua in shutdown. the 2.5 to 6.5v input voltage range makes the SP3406 ideally suitable for single li-ion, two to four aa battery-powered applications. in low dropout operation mode, the duty cycle can reach to 100%, extending battery life in portable systems. pwm pulse skipping mode operation provides very low output ripple voltage for noise sensitive applications. switching frequency is internally set at 1.5mhz, allowing the use of small surface mount inductors and capacitors. the internal synchronous switch increases efficiency and eliminates the need for an external schottky diode. low output voltages are easily supported with the 0.6v feedback reference voltage. the sp 3406 is available in a small sot-23-5 package. digital camera pda hand held communication equipment wireless and dsl modems portable instrument microprocessor and dsp core supplies mid or upmc features pin configuration ( sot-23-5l) high efficiency: up to 96%; 1.5mhz constant switching frequency; 600ma output current at vin=3v; integrated main switch and synchronous rectifier, no schottky diode required; 2.5 to 6.5v input voltage; output voltage as low as 0.6v; 100% duty cycle in dropout; quiescent current: 30ua(input<4.2v); slope compensated current mode control for excellent line and load transient response; short circuit protection and thermal fault protection; <1ua shutdown current; soft start; part marking
2012/11/15 v. 1 page 2 SP3406 600ma buck converter typical application circuit r 2 vout = 0.6 (1+ ) r1 pin description & electrical characteristics pin symbol description operating rating min. typ. max. unit 1 run control input -0.3 v in v 2 gnd ground -0.3 v in +0.3 v 3 sw switch node connect to inductor -0.3 v in +0.3 v 4 v in supply voltage -0.3 6.5 v 5 v fb feedback -0.3 v in v block diagram ordering information part number package part marking SP3406s25rgb sot-23-5l 3406 SP3406s25rgb : 7 tape reel; pb C free, halogen-fr ee
2012/11/15 v. 1 page 3 SP3406 600ma buck converter absoulte maximum ratings (ta=25 , unless otherwise specified.) the following ratings designate persistent limits b eyond which damage to the device may occur . symbol parameter value unit v in dc supply voltage -0.3 ~ 6.5 v i out sw current, source or sink 1.3 a t j operating junction temperature range 125 t stg storage temperature range -65 to 150 t lead lead soldering temperature for 5 sec. 260 t ope operation temperature range -40 ~ 85 r ? jc thermal resistance junction C case (*) 250 /w electrical characteristics (unless otherwise stated, these specifications appl y t a =25c; v in =3.6v) symbol parameter conditions min. typ. max. unit supply v in supply voltage 2.5 6.5 v i in input dc bias current active mode v fb = 0.5v or v out = 90%, i load = 0a 300 400 ua input dc bias current sleep mode v fb = 0.62v or v out = 103%, i load = 0a 20 35 ua input dc bias current shutdown mode v run <0v, v in = 4.2v 0.1 1 ua v run run threshold 0.3 1 1.5 v i run run leakage current 0.01 1 ua feedback v fb regulated feedback voltage 0.588 0.6 0.612 v v fb reference voltage line regulation v in = 2.5v to 5.5v 0.04 0.4 %/v i fb feedback current 30 na v loadreg output voltage load regulation 0.5 % i peak peak induct current v in = 3v, v fb = 0.5v, duty cycle < 35% 0.75 1 1.25 a switching regulator r pmos * r ds( on) for p mosfet i sw = 100ma 400 500 m ? r nmos * r ds( on) for n mosfet i sw = 100ma 350 450 m ? i lsw sw leakage current v run = 0v, v in = 5v, v sw = 0v or 5v 0.01 1 ua f osc oscillator frequency v fb = 0v or v out = 0v v fb =0.6v or v out =100% 1.2 1.5 1.8 mhz * guaranteed by design
2012/11/15 v. 1 page 4 SP3406 600ma buck converter typical performance characteristics t a = +25 ; unless otherwise noted. output voltage vs. load current oscillator frequency vs. supply voltage efficiency vs. output current output voltage vs. input voltage normal operating waveforms v in =4.2v,v out =2.5v,i out =0.6a short circuit protection waveforms v in =4.2v,v out =2.5v,i out =0.6a ch1 v sw , ch2 i l , ch3 v out
2012/11/15 v. 1 page 5 SP3406 600ma buck converter sot 23-5l package outline
2012/11/15 v. 1 page 6 SP3406 600ma buck converter information provided is alleged to be exact and con sistent. sync power corporation presumes no respon sibility for the penalties of use of such information or for any violation of patents or other rights of third parties, which may result from its use. no license is granted by alle gation or otherwise under any patent or patent righ ts of sync power corporation. conditions mentioned in this pu blication are subject to change without notice. th is publication surpasses and replaces all information previously supplied. sync power corporation produc ts are not authorized for use as critical components in li fe support devices or systems without express writt en approval of sync power corporation. ?the sync power logo is a registered trademark of sync power corporation ?2012 sync power corporation C printed in taiwan C all rights reserved sync power corporation 7f-2, no.3-1, park street nankang district (nksp), taipei, taiwan, 115, r.o.c phone: 886-2-2655-8178 fax: 886-2-2655-8468 http://www.syncpower.com
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