advanced power electronics corp. fast transient response linear controller features description low esr output capacitor (mlcc and poscap) applicable 0.5v reference voltage with 2% accuracy internal soft-start support vid application circuit integrated hard short-circuit protection fast transient response power ok output with a delay time adjustable output voltage down to 0.5v over-temperature protection rohs compliant & haloge free data and specifications subject to change without notice 20130108v1.1 APE8858A typical application 1 the APE8858A is an ultra low output voltage linear n- fet controller. this product is specifically designed to provide well supply voltage for front-side-bus termination on motherboards and nb applications. the APE8858A integrates many functions. a power-on-reset (por) circuit monitors supply voltages to prevent wrong operations. a pok indicates the output status with time delay which is set internally. it can control other converter for power sequence. the APE8858A can be enabled by other power system. a 0.5v reference voltage with 2% accuracy provide tight regulation of the output voltage, enable control, open drain power good signal, under-voltage protection and soft start. the APE8858A is available in a space saving sot-26 package. 0.1uf c vcc 100k r pok q1 ap4434agh 10uf cin 26k r1 10k r2 v cc =5v 10uf cout v in v out =1 .8 v cf fb pok vcc gnd en drv ape 8 8 5 8a
advanced power electronics corp. APE8858A absolute maximum ratings (at t a =25c) vcc ----------------------------------------------------------- -0.3v to 7v drv to gnd ------------------------------------------------ - -0.3v to vcc+0.3v other pin ----------------------------------------------------- - -0.3v to 6v power dissipation (sot-26) ---------------------------- 0.4w storage temperature range --------------------------- - -65 to 150c operating temperature range ------------------------ - -40 to 85c junction temperature range -------------------------- - -40 to 125c package / ordering information electrical specifications (v in =1.5v, v shdn =v in , t a =25 c, c in =c out =1f, unless otherwise noted.) parameter sym test condition min typ max units supply voltage range v cc 4.5 - 5.5 v input voltage uvlo threshold v uvlo v cc rising - 3.75 - v input voltage uvlo hysteresis v hyst v cc falling - 0.25 - v supply current i cc en= v cc - 0.4 0.8 ma shutdown current i sd en= 0v -1 - 1 ua feedback voltage v fb 0.49 0.5 0.51 v feedback pin input current i fb vfb =0.5v -100 - 100 na soft start time tss - 1 - ms venh enable 1.3 - - v enl disable - - 0.5 en pin input current i en i out =0ma, v in =5v -1 - +1 ua output voltage uvlo threshold v th(uv) v fb falling 0.2 0.25 0.3 v ton duty t on v fb < 0.25v - 30 - % i drv(src) sourcing,v fb =0.48v - 20 - i drv(sink) sinking ,v fb =0.52v - 20 - drv pin output voltage v drv v fb =0.48v,v cc =5v, no load 4.8 - 5.0 v 93% 95% drv output current ma 2 en pin logic high threshold voltage v 97% pok threshold voltage for power ok vfb v pok v fb rising rth ja =250c/w (top view) sot-26 3 2 6 4 1 gnd fb vcc drv 5 pok en package type y : sot-26 APE8858A x
advanced power electronics corp. APE8858A electrical specifications(cont.) parameter sym test condition min typ max units pok low voltage pok sinks 1ma - 50 100 mv pok delay time t delay 0.8 2 10 ms thermal shutdown temperature tsd - 150 - c thermal shutdown hysteresis - 50 - c pin descriptions pin symbol pin description fb feedback pin gnd common ground pin drv gate drive to n-fet pok power ok output pin h : normal operation l : shutdown vcc input voltage block diagram vfb pok threshold voltage for power not ok v pnok v fb falling 86% 89% 93% 3 en power on reset enable thermal shutdown uv error amp soft -start and control logic delay bandgap 0.25v pok 95% v ref gnd en vcc pok fb drv
advanced power electronics corp. APE8858A function descriptions power-on-reset internal soft-start output voltage regulation under-voltage protection (uvp) thermal shutdown 4 a power-on-reset (por) circuit monitors input voltages at vcc pins to prevent wrong logic controls. the por function initiates a soft-start process after the supply voltages exceed the rising por threshold voltages during powering on. the por function also pulls low the pok pin regardless the output voltage when the vcc voltage falls below it?s fallin g por threshold. an internal soft-start function controls rise rate of the output voltage to limit the current surge at start-up. the typical soft-start interval is about 1ms. an error amplifier working with a temperature compensated 0.5v reference and an output nmos regulates output to the preset voltage. the error amplifier designed with high bandwidth and dc gain provides very fast transient response and less load regulation. APE8858A monitors the voltage on fb pin after soft-start process is finished. therefore the uvp is disabling during soft-start. when the voltage on fb pin falls below the under-voltage threshold, the uvp circuit shuts off the output immediately. after a while ( ~ 70% duty ) , APE8858A starts a new soft-start to regulate output. a thermal shutdown circuit limits the junction temperature of APE8858A. when the j unction temperature exceeds +150 c, a thermal sensor turns off the output nmos, allowing the device to cool down. the regulator regulates the output again through initiation of a new soft-start cycle after the junction temperature cools by 50c, resulting in a pulsed output during continuous thermal overload conditions.
advanced power electronics corp. typical performance characteristics 5 APE8858A fig.6 shutdown current vs. temperature fig.4 uvlo vs. temperature fig.3 feedback voltage vs. temperature fig.5 supply current vs. temperature fig.2 load transient, 3vi to 1.8vo fig.1 hard short circuit protection pok vout vdrv iout with cf=1nf without cf iout=0a~1.5a 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 -40 -20 0 20 40 60 80 t j (c) v cc (v) rising falling 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 -40 -20 0 20 40 60 80 t j (c) i q (ma) 480 484 488 492 496 500 504 508 512 516 520 -40 -20 0 20 40 60 80 100 120 t j (c) v fb (mv) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 -40 -20 0 20 40 60 80 t j (c) i sd (ua)
advanced power electronics corp. application circuit vid1 vid0 vo (v) 0 0 0.675 0 1 0.725 1 0 0.8 1 1 0.9 6 APE8858A with output voltage step function from 0.9v to 0.675v APE8858A fb pok vcc gnd en drv APE8858A u1 0.1uf c1 100k r pok ap4434agh q1 10uf cin 10k r1 30k r2 en v cc =5v v in =1.05v v out =0.9v/6a 1nf cf pok + 330uf (esr>15m ? ) cout 34k r4 71k r3 q3 q2 4. 7n f c2 4. 7n f c3 10k r5 10k r6 vid0 vid1
advanced power electronics corp. APE8858A marking information sot-26 7 hess part number : he date code ss:2004,2008,2012? ss :2003,2007,2011? s s:2002,2006,2010? ss :2001,2005,2009?
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