advanced power electronics corp. features description input voltage 3.6v to 23v output voltage 0.8v to vcc duty ratio 0% to 100% pwm control oscillation frequency 330khz typ. current limit(cl), enable function. thermal shutdown function. short circuit protect (scp). built-in internal sw p-channel mos. sop-8l pb-free package. v out 1.8 v 2.5v 3.3v 5v i out =3.5a 12uh 15uh 18uh 22uh data and specifications subject to change without notice pwm control 3.5a step-down converter typical application 1 l1 recommend value (v in =12v ) package ordering information 200808292 ape1802 ape1802 consists of step-down switching regulator with pwm control. these devise include a reference voltage source, oscillation circuit, error amplifier, internal pmos and etc. ape1802 provides low-ripple power, high efficiency, and excellent transient characteristics. the pwm control circuit is able to the duty ratio linearly form 0 up to 100%. an enable function, an over current protect function and short circuit protect function are built inside, and when ocp or scp happens, the operation frequency will be reduced. a lso, an internal compensation block is built in to minimum external component count. with the addition of an internal p-channel power mos, a coil, capacitors, and a diode connected externally, these ics can function as step-down switching regulators. they serve as ideal power supply units for portable devices when coupled with the sop-8l package, providing such outstanding features as low current consumption. since this converter can accommodate an input voltage up to 23v, it is also suitable for the operation via an ac adapter. package type m : sop-8 ape1802x r1 r2 vfb = 0.8v ; r2 suggest 0.8k ~ 6k vout = vfb x (1 + ) c2 470uf c3 0.1uf c4 470uf 1 2 l1 22uh r1 30k r2 5.6k vin+12v on/off c1 1nf vout = 5v/3.5a r3 1.5k r4 100k d1 b340 c8 0.1uf fb 1 en 2 ocset 3 vcc 4 sw 5 sw 6 vss 7 vss 8 ape1802 c6 0.1uf
advanced power electronics corp. ape1802 absolute maximum ratings (at t a =25c) v cc pin voltage(v cc ) ------------------------------------- - vss - 0.3 to vss + 25v feedback pin voltage(v fb ) ----------------------------- - v ss -0.3v to v cc on/off pin voltage(v en ) ------------------------------ - v ss -0.3v to v cc + 0.3v switch pin voltage(v sw ) --------------------------------- - v ss -0.3v to v cc + 0.3v power dissipation(p d ) ------------------------------------ - internally limited storage temperature range(t st ) --------------------- -40c to 150c operating temperature range(t op ) ------------------ -20c to 125c operating supply voltage(vop) ----------------------- - +3.6v to +23v output current (i out ) -------------------------------------- 0 to 3.5a peak current (i peak ) ---------------------------------------- 6a thermal resistance from junction to case(rth jc ) 25c/w 70c/w note. rth ja is measured with the pcb copper area(need connect to sw pins) of approx. 1 in 2 (multi-layers) package information electrical specifications (v in =12v, t a =25 : , unless otherwise specified) parameter sym test condition min typ max units feedback voltage v fb i out =0.1a 0.784 0.8 0.816 v quiescent current i ccq v fb =1.2v force driver off - 3 5 ma feedback bias current i fb i out =0.1a - 0.1 0.5 ua shutdown supply current i sd v en =0v - 2 10 ua ocset pin bias current i ocset 95 110 140 ua switch current i sw 45 - - a line regulation ? v out /v out v cc = 8v~23v, i out =0.2a - 1 2 % load regulation ? v out /v out i out = 0.1a to 3.5a - 0.2 0.5 % oscillation frequency f osc sw pin 260 330 400 khz 2 thermal resistance from junction to ambient(rth ja ) ( top view ) 1 2 3 4 8 7 6 5 fb ocset sop?8l ape1802 vcc en vss vss sw sw
advanced power electronics corp. ape1802 electrical specifications(cont.) v sh high (regulator on) 2 - - v v sl low (regulator off) - - 0.8 v i sh v en =2.5v(on) - 20 - ua i sl v en =0.3v(off) - -10 - ua v cc =5v, v fb =0v - 80 140 v cc =12v, v fb =0v - 55 90 i out =2a 92 i out =3.5a 90 pin descriptions pin symbol pin description v ss gnd pin fb feedback pin power -off pin h : normal operation(step-down) l : step-down operation stopped (all circuits deactivated) ocset add an external resistor to set max switch output current. sw switch pin. connect external inductor & diode here. v cc ic power supply pin block diagram effi - - % 3 en en pin logic input threshold volta g en pin input current internal mosfet r ds(on) r ds(on) m ?
advanced power electronics corp. ape1802 function pin description pwm control rds(on) current limiting (normally, the i sw(max) setting more than i out 1.0a ). example: i sw = (110u x 1.5k + 0.08)/ 55m= 4.75a (vin=12v) i sw = (110u x 2.7k + 0.08)/ 80m= 4.7a (vin=5v) setting the output voltage v out r2 r1 1.3k 6.8k 5.6k 30k 1.5k 4.7k 5.6k 18k 2.2k 4.7k 5.6k 12k 1.8v 2k 2.5k 1.5v 2.2k 2k 1.2v 3k 1.5k 1.0v 3k 0.75k 4 5v 3.3v 2.5v r2 setting 5.6k that system operation current (no load) can be reducing to under 4ma. the ape1802 consists of dc/dc converters that employ a pulse-width modulation (pwm) system. in converters of the ape1802, the pulse width varies in a range from 0 to 100%, according to the load current. the ripple voltage produced by the switching can easily be removed through a filter because the switching frequency remains constant. therefore, these converters provide a low-ripple power over broad ranges of input volta g e and load current. application circuit item shows the basic application circuit with ape1803 adjustable output version. the external resistor sets the output according to the following equation : v out = 0.8v x (1+r1/r2) table1 resistor select for output voltage setting the current limit threshold is setting by the external resistor (r3) connecting from vcc supply to ocset pin. the internal 110ua sink current crossing the resistor sets the voltage at pin of ocset. when the pwm voltage is less than the voltage at ocset, an over-current condition is triggered. please refer to the formula for setting the current limit value: r i i ds(on) ocset sw(min) 08 . 0 r3 + = + =
advanced power electronics corp. ape1802 pcb layout guide 5 if you need low t c & t j or large pd(power dissipation), the dual sw pins (5 & 6) on the sop-8l package are internally connected to die pad, the pcb layout should allow for maximum possible copper area at the sw pins. 1. connect c3 to vcc pin as closely as possible to get good power filter effect. 2. connect r3 to vcc pin as closely as possible. 3. connect ground side of the c2 & d1 as closely as possible.
. ape1802 typical characteristics vfb vs vin iccq vs vin vfb vs vin 0.780 0.784 0.788 0.792 0.796 0.800 0.804 0.808 0.812 0.816 0.820 4 6 8 10 12 14 16 18 20 22 24 vfb (v) vin (v) iccq vs vin 0.0 1.0 2.0 3.0 4.0 5.0 6.0 4 6 8 1012141618202224 vin (v) iccq (ma) fosc vs vin fosc vs temperature fosc vs vin 280.0 290.0 300.0 310.0 320.0 330.0 340.0 350.0 360.0 4 6 8 1012141618202224 vin (v) f osc (khz ) fosc vs temperature 280.0 290.0 300.0 310.0 320.0 330.0 340.0 350.0 360.0 -20 0 20 40 60 80 100 120 temp ( ) fosc(khz) vfb vs temperature iccq vs temperature vfb vs temperature 0.780 0.785 0.790 0.795 0.800 0.805 0.810 0.815 0.820 -20 0 20 40 60 80 100 120 temp ( ) vfb(v) iccq vs temperature 0.0 1.0 2.0 3.0 4.0 5.0 6.0 -20 0 20 40 60 80 100 120 temp ( ) iccq(ma ) 6 a d v a n ced p o w e r electr o n i cs c o r p .
. ape1802 typical characteristics output ripple (v in =12v, v out =5v, i out =3a) power on test wave (v in =12v, v out =5v, i out =3a ) load transient response (v in =12v, v out =5v, i out =0.1~3a) en pin on test wave (v in =12v, v out =5v, i out =3a ) efficiency (v in =12v, v out =5v) efficiency (v in =12v, v out =3.3v) vou t=5 v 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0.0 1.0 2.0 3.0 iout(a) efficiency(%) vou t=3 .3 v 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0.0 1.0 2.0 3.0 iout(a) efficiency(%) sw sw i sw v out v in sw i sw sw i sw v out v in v out (ac) v out v out (ac) i sw adva nced power electronics corp. 7
millimeters symbols min nom max a 1.35 1.55 1.75 a1 0.10 0.18 0.25 b 0.33 0.41 0.51 c 0.19 0.22 0.25 d 4.80 4.90 5.00 e 5.80 6.15 6.50 e1 3.80 3.90 4.00 e g l 0.38 0.90 0.00 4.00 8.00 1.all dimension are in millimeters. 2.dimension does not include mold protrusions. part marking information & packing : so-8 1.27 typ 0.254 typ package outline : so-8 advanced power electronics corp. e b 1 34 5 6 7 8 2 d e1 a1 a g part number 1802 m ywwsss package code date code (ywwsss) y last digit of the year ww week sss sequence e
|
