advanced power electronics corp. features description very low supply current is 22ua (typ.) maximum shutdown current <1ua output voltage is available form 2.5v to 5.0v by 0.1v steps output voltage accuracy 5% output current up to 100ma low ripple and low noise very low start-up voltage high efficiency (vout = 5v typ. 87%) few external components internal soft-start low profile: sot-23-5l pb-free identification code see page8. data and specifications subject to change without notice 200907313 ape2902 typical application order/marking information 1 micropower vfm step-up dc/dc converter the ape2902 is a high efficiency vfm step-up dc/dc converter for small, low input voltage or battery powered systems with ultra low quiescent supply current. the a pe2902 accept a positive input voltage from start-up voltage to v out and convert it to a higher output voltage in the 2.5 to 5v range. the ape2902 combine ultra low quiescent supply current and high efficiency to give maximum battery life. the high switching frequency and the internally limited peak inductor current permits the use of small, low cost inductors. only three external components are needed an inductor a diode and an output capacitor. the ape2902 is suitable to be used in battery powered equipment where low noise, low ripple and ultra low supply current are required. operating shutdown function is outside controlling. if en connects to gnd, the ic was been shut down and then the supply current is lower to 1ua.the a pe2902 is available in very small package: sot-23-5l. typical applications are pagers, cameras & video camera, cellular telephones, wireless telephones, palmtop computer, battery backup supplies, battery powered equipment. c2 0.1uf enable input vout c3 47uf vin c4 0.1uf l1 47uh 1 2 c1 100uf d1 b140 1 2 u1 ape2902 sw gnd out nc en package type y5 : sot-23-5l ape2902xx-xx 25 : 2.5v 26 : 2.6v 27 : 2.7v : : 50 : 5.0v vout y5r : sot-23-5l 22 : 2.2v t&xyw ww : 01~26(a~z) 27~52(a~z) year : 8 = 2008 a = 2010 identification code
advanced power electronics corp. ape2902 absolute maximum ratings (t a = 25 o c) vin supply voltage(v in ) ?????????? ? 5.5 v sw voltage(v sw ) ????????????? ? 5.5 v out voltage(v out ) ????????????? 5.5 v en pin voltage(v en ) ???????????? ? 5.5 v power dissipation(p d ) ??????????? ? ( t j -t a ) / r thja w storage temperature range(t st ) ?????? ? -40c to 150c operating junction temperature range(t op ) ? ? -20c to + 100c thermal resistance from junction to case(rth jc ) 110c/w 250c/w note : rth ja is measured with the pcb copper area of approximately 1 in2(multi-layer). package information electrical specifications ( v in =1.8v, i out =10ma, t a =25 o c, unless otherwise specified) parameter sym test condition min typ max units output voltage accuracy v out -5 - 5 % start-up voltage(v in -v f )(note 1) v start-up i out =1ma, v in =rising from 0 to 2v - 0.8 1.2 v hold-on voltage v hold i out =1ma, v in =falling from 2 to 0v 0.6 - - v supply current i supply no load - 22 - ua shutdown current i sd v en =0v - - 1 ua internal switch r dson r sw(dson) i sw =150ma - 850 - m ? internal leakage current i sw(leak) v sw =4v, forced v out =3.8v - - 0.5 ua maximum oscillator frequency f osc - 150 - khz oscillator duty on d on to be measured on sw pin - 77 - % v enh driver on 0.75 - - v enl driver off - - 0.2 i enh v en =v in - - 0.1 i enl v en =0v - - -0.1 vout=2.5v~3.0v, i out =50ma - 82 - % vout=3.1v~4.0v, i out =50ma - 83 - % vout=4.1v~5.0v, i out =50ma - 87 - % note 1: the minimum input voltage for the ic start-up is strictly a function of the vf catch diode. 2 thermal resistance from junction to ambient(rth ja ) efficiency enable input threshold enable input current v ua sw gnd en vout nc top view 1 23 4 5 ap2902y5r sot-23-5l en nc sw gnd vout top view ap2902y5 1 23 4 5 sot-23-5l
advanced power electronics corp. ape2902 pin descriptions pin symbol pin description sw switch pin. connect external inductor & diode here. gnd gnd pin out output voltage en chip enable pin block diagram operation 3 the ape2902 architecture is built around a vfm control logic core, switching frequency is set through a built in oscillator. t on time is fixed (typ. 5us) while t off time is determined by the error amplifier output, a logic signal coming from the comparison made by the error amplifier stage between the signal coming from the output voltage divider network and the internal band-gap voltage reference (vref). t off reaches a minimum (typ. 1.7us) when heavy load conditions are met (clock frequency 150khz). an over current conditions, through the internal power switch, causes a voltage drop v sw =r ds(on) x i sw and the v sw limiter block forces the internal switch to be off, so narrowing t on time and limiting internal power dissipation. in this case the switching frequency may be higher than the 150khz set by the internal clock generator. vfm control ensures very low quiescent current and high conversion efficiency even with very light loads. since the output voltage pin is also used as the device supply voltage, the versions with higher output voltage present an higher internal supply voltage that results in lower power switch r ds(on) , slightly greater output power and higher efficiency. moreover, bootstrapping allows the input voltage to sag to 0.6v (at i out =1ma) once the system is started. if the input voltage exceeds the output voltage, the output will follow the input, however, the input or output voltage must not be forced above 5.5v. sw gnd - + vfm control driver - + v ref out error amp. limiter amp. en chip enable
advanced power electronics corp. ape2902 application information input/output capacitor selection inductor selection diode selection pcb layout guide 4 the output ripple voltage, as well as the efficiency, is strictly related to the behavior of these elements. the output ripple voltage is the product of the peak inductor current and the output capacitor equivalent series resistance (esr). best performances are obtained with good high frequency characteristics capacitors and low esr. the best compromise for the value of the output capacitance is 47f tantalum capacitor; lower values may cause higher output ripple voltage and lower efficiency without compromising the functionality of the device. an input capacitor is required to compensate, if present, the series impedance between the supply voltage source and the input voltage of the application. a 47 h inductor is recommended for most ape2902 applications. however, the inductance value is not critical, and the ape2902 will work with inductors in the 33h to 120h. schottky diodes with higher current ratings usually have lower forward voltage drop, larger diode capacitance and fast reverse recovery, it is the ideal choices for ape2902 applications. the forward voltage drop of a schottky diode represents the conduction losses in the system, while the diode capacitance (c t or c d ) represents the switching losses. for diode selection, both forward voltage drop and diode capacitance need to be considered. when laying out the pc board, the following suggestions should be taken to ensure proper operation of the ape2902. these items are also illustrated graphically in below. 1. the power traces, including the g nd trace, the sw trace and the v in trace should be kept short, direct and wide to allow large current flow. put enough multiply-layer pads when they need to change the trace layer. 2. do not trace signal line under inductor.
advanced power electronics corp. ape2902 typical performance characteristics 5 t a =25 , input voltage vs. output voltage 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 0 1 0 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 0 2 2 5 2 5 0 output current (ma) output voltage (v) iout=50ma, output voltage vs. temperature 2.80 2.85 2.90 2.95 3.00 3.05 - 2 0 0 2 5 5 0 7 5 1 0 0 temperature ( ) output vlotage (v) vin=1.8v, output voltage vs. temperature 2.30 2.40 2.50 2.60 2.70 2.80 2.90 3.00 3.10 - 2 0 0 2 5 5 0 7 5 1 0 0 temperature ( ) output vlotage (v) start-up voltage vs. output current 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1 1 0 2 5 5 0 7 5 1 0 0 output current (ma) start-up vlotage (v) iout=1ma, start-up voltage vs. temperature 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 - 2 0 0 2 5 5 0 7 5 1 0 0 temperature ( ) start-up vlotage (v) iout=1ma, hold-on voltage vs. temperature 0.0 0.1 0.1 0.2 0.2 0.3 0.3 0.4 0.4 - 2 0 0 2 5 5 0 7 5 1 0 0 temperature ( ) hold-on vlotage (v) i out =250ma i out =50ma i out =0ma i out =100ma i out =150ma i out =200ma v in =2.4v v in =1.8v vin=1.2v v in =0.9v v in =1.2v v in =1.5 v in =1.8v v in =2.4v
advanced power electronics corp. ape2902 typical performance characteristics 6 input voltage vs. supply current 0 5 10 15 20 25 30 35 40 45 50 1 . 2 1 . 5 1 . 8 2 . 4 input voltage (v) supply current (ua) supply current vs. temperature 0 100 200 300 400 500 600 700 800 - 2 0 0 2 5 5 0 7 5 1 0 0 temperature ( ) supply current (ua) maximum oscillator frequency vs. temperature 0 20 40 60 80 100 120 140 160 180 200 - 2 0 0 2 5 5 0 7 5 1 0 0 temperature ( ) maximum oscillator frequency (khz) oscillator duty-on vs. temperature 0 10 20 30 40 50 60 70 80 90 100 - 2 0 0 2 5 5 0 7 5 1 0 0 temperature ( ) oscillator duty-on (%) ape2902-30, efficiency vs. output current 0 10 20 30 40 50 60 70 80 90 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 0 2 2 5 2 5 0 output current (ma) efficiency (%) ape2902-30, iout=50ma, efficiency vs. temperature 74 76 78 80 82 84 86 88 90 - 2 0 0 2 5 5 0 7 5 1 0 0 temperature ( ) efficiency (%) v in =2.4v v in =1.8v v in =1.2v v in =0.9v v in =1.2v v in =1.5v v in =1.8 v in =2.4v v in =2.4v v in =1.2v v in =1.5v v in =1.8v ape2902-33 ape2902-30 ape2902-28
advanced power electronics corp. ape2902 typical performance characteristics v in =1.8v, v out =2.8v, i out =10ma, en=5 to 0v v in =1.8v, v out =2.8v, i out =10ma, en=0 to 5v ch1: v in , 1v/div ch1: v in , 1v/div ch2: v out , 1v/div ch2: v out , 1v/div ch3: v sw , 2v/div ch3: v sw , 2v/div ch4: v en , 5v/div ch4: v en , 5v/div 7 enable off sequence enable on sequence vin=1.8v, efficiency vs. temperature 50 55 60 65 70 75 80 85 90 - 2 0 0 2 5 5 0 7 5 1 0 0 temperature ( ) efficiency (%) sw switching current limit vs. temperature 740 760 780 800 820 840 860 880 900 - 2 0 0 2 5 5 0 7 5 1 0 0 temperature ( ) sw switching current limit (ma) i out =50ma i out =100ma i out =150ma i out =200ma i out =250ma vin vout sw ven vin vout sw ven
package outline : sot-23-5l millimeters min nom max a 1.00 1.10 1.30 a1 0.00 --- 0.10 a2 0.70 0.80 0.90 b 0.35 0.40 0.50 c 0.10 0.15 0.25 d 2.70 2.90 3.10 e 1.50 1.60 1.80 e --- 1.90(typ) --- h 2.60 2.80 3.00 l 0.37 --- --- 1159 e2 --- 0.95(typ) --- note 1 package body sizes exclude mold flash protrusions or gate burrs. note 2 tolerance 0.1000 mm(4mil) unless otherwise spe- cified. note 3 coplanarity 0.1000 mm note 4 dimension l is measured in gage plane. part marking information & packing : sot-23 -5l advanced power electronics corp. symbols t&xss part number : t&x (identification code) date code 8 part number identificatio n code part number identificatio n code ape2902y5/y5r-2.2v to/to1 ape2902y5/y5r-3.8v tn/tn1 ape2902y5/y5r-2.5v ta/ta1 ape2902y5/y5r-3.9v to/to1 ape2902y5/y5r-2.6v tb/tb1 ape2902y5/y5r-4.0v tp/tp1 ape2902y5/y5r-2.7v tc/tc1 ape2902y5/y5r-4.1v tq/tq1 ape2902y5/y5r-2.8v td/td1 ape2902y5/y5r-4.2v tr/tr1 ape2902y5/y5r-2.9v te/te1 ape2902y5/y5r-4.3v ts/ts1 ape2902y5/y5r-3.0v tf/tf1 ape2902y5/y5r-4.4v tt/tt1 ape2902y5/y5r-3.1v tg/tg1 ape2902y5/y5r-4.5v tu/tu1 ape2902y5/y5r-3.2v th/th1 ape2902y5/y5r-4.6v tv/tv1 ape2902y5/y5r-3.3v ti/ti1 ape2902y5/y5r-4.7v tw/tw1 ape2902y5/y5r-3.4v tj/tj1 ape2902y5/y5r-4.8v tx/tx1 ape2902y5/y5r-3.5v tk/tk1 ape2902y5/y5r-4.9v ty/ty1 ape2902y5/y5r-3.6v tl/tl1 ape2902y5/y5r-5.0v tz/tz1 ape2902y5/y5r-3.7v tm/tm1
|
