200828071pre-1/7 this datasheet contains new product information. advanced power electronics corp. reserves the rights to modify the product specification without notice. no liability is assumed as a result of the use of this product. no rights under any patent accompany the sale of the product. APE1720 200khz, 1.5a pwm buck dc/dc converter ? general description the APE1720 series are monolithic ic designed for a step-down dc/dc converter, and own the ability of driving a 1.5a load without additional transistor. it saves board space. the external shutdown function can be controlled by logic level and then come into standby mode. the internal compens ation makes feedback control having good line and load regulation without external design. regarding protected function, thermal shutdown is to prevent over tem perature operating from damage, and current limit is against over current operating of th e output switch. if cu rrent limit function occurs and v fb is down below 0.5v, the swit ching frequency will be reduced. the APE1720 series operates at a switching frequency of 200khz thus allow smaller sized filter components than what would be needed with lower frequency switching regulators. other features include a guaranteed +3% to lerance on output voltage under specified input voltage and output load conditions, the chips are available in a standard 8-lead sop package. ? feature s - output voltage: adjustable output version. - adjustable version output vo ltage range: 0.75v to 22v+3%. - 200khz fixed switching frequency. - voltage mode non-synchronous pwm control. - thermal-shutdown and current-limit protection. - on/off shutdown control input. - operating voltage can be up to 24v. - output load current: 1.5a. - sop-8l pb-free packages. - low power standby mode. - built-in switching transistor on chip. adva nced power electronics corp.
2/7 APE1720 ? block diagram 200khz osc. start up + + _ + _ thermal shutdown control + driver comp. comp. vss sw en fb 200mv 220mv _ comp. v cc current limit + _ amp comp. current source bias 0.75v reference 2.5v regulator ? pin assignment the package of APE1720 is sop-8l; the pin assignment is given by: name description v cc operating voltage input sw switching output fb output voltage feedback control en on/off shutdown high pe1720m v ss gnd pin ? order/marking information order information top marking packa g e type m : s o p - 8 l APE1720 x ywwsss 1720m part number id code: internal ww: 01~52 year : 7 = 2007 adva nced power electronics corp.
3/7 APE1720 ? absolute maximum ratings characteristics symbol rating unit maximum supply voltage v cc +26 v on/off pin input voltage v en -0.3 to v cc v feedback pin voltage v fb -0.3 to 12 v output voltage to ground v out -0.8 v power dissipation internally limited pd ( t j -t a ) /
4/7 APE1720 ? application circuit (1) adjustable output voltage version c2 0.1uf d1 b240a l1 33uh c3 220uf c1 220uf u1 APE1720 1 2 3 4 5 6 7 8 vcc sw fb en vss vss vss vss vout=5v/1.5a vin=12v c6 0.1uf r2 1.2k r1 6.8k (2) en pin with delayed startup c2 0.1uf d1 b240a l1 33uh c3 220uf c1 220uf u1 APE1720 1 2 3 4 5 6 7 8 vcc sw fb en vss vss vss vss vout=5v/1.5a vin=12v on/off c6 0.1uf r2 1.2k r1 6.8k c4 0.1uf r3 100k vout = v fb
5/7 APE1720 ? function descriptions pin functions vcc this is the positive input supply for the ic switching regulator. a suitable input bypass capacitor must be pres ented at this pin to minimi ze voltage transients and to supply the switching currents needed by the regulator. vss circuit ground. sw internal switch. the voltage at this pin switches between (+v cc ? v sat ) and approximately ? 0.5v, with a duty cycle of approximately v out / v cc . to minimize coupling to sensitive circuitry, the pc boar d copper area connected to this pin should be minimized. feedback senses the regulated output voltage to complete the feedback loop. en allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 10ua. pulling this pin below a threshold voltage of approximately 0.5v shut s the regulator down, and pulling this pin above 2.0v (up to a maximum of vcc) turns the regulator on. thermal considerations the sop-8 package needs a heat sink under most conditions. the size of the heat sink depends on the input voltage, the output voltage, the load current and the ambient temperature. the APE1720 junction temperature rises above ambient temperature for a 1.5a load and di fferent input and output voltages. for the best thermal performance, wide copper traces and generous amounts of pcb copper (need connect to the v ss pins) should be used in the board layout, (one exception is the sw pin, which should no t have large areas of copper.) large areas of copper provide the best transfer of heat (lower thermal resi stance) to the surrounding air, and moving air lowers the thermal resistance even further. adva nced power electronics corp.
6/7 APE1720 ? typical characteristics vfb vs vin iccq vs vin vfb vs vin 0.71 0.72 0.73 0.74 0.75 0.76 0.77 4 6 8 101214161820222426 vin(v) vfb(v) iccq vs vin 0.00 1.00 2.00 3.00 4.00 5.00 6.00 4 6 8 101214161820222426 vin(v) iccq(ma) fosc vs vin fosc vs temperature fosc vs vin 180 190 200 210 220 230 240 4 6 8 10 12 14 16 18 20 22 24 26 vin(v) fosc(khz) fosc vs temp 140 150 160 170 180 190 200 210 220 230 240 -20 0 20 40 60 80 100 120 temp ( : ) fosc(khz) vfb vs temperature iccq vs temperature vfb vs temp 0.745 0.748 0.751 0.754 0.757 0.760 0.763 -20 0 20 40 60 80 100 120 temp ( : ) vfb(v) iccq vs temp 0.00 1.00 2.00 3.00 4.00 5.00 6.00 -20 0 20 40 60 80 100 120 temp ( : ) iccq(ma) adva nced power electronics corp.
7/7 APE1720 ? typical characteristics output ripple (v in =12v, v out =3.3v, i out =1.5a) power on test wave (v in =12v, v out =3.3v, i out =1.5a) load transient response (v in =12v, v out =3.3v, i out =0.1~1.5a) en pin on test wave (v in =12v, v out =3.3v, i out =1.5a) efficiency (v in =12v, v out =5v) efficiency (v in =12v) vin=12v 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 0.00.51.01.5 iout(a ) efficiency(%) vin=12v 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 0.0 0.5 1.0 1.5 io ut(a) efficiency(%) vout=5v vout=3.3v vout=2.5v vout=1.8v vout=1.2v sw i sw sw i sw v out v in sw i sw sw i sw v out v in v out (ac) v out (ac) v in v in adva nced power electronics corp.
package outline : sop-8l 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 e1 3.80 3.90 4.00 e 5.80 6.15 6.50 l 0.38 0.71 1.27 0 4.00 8.00 e 1.all dimension are in millimeters. 2.dimension does not include mold protrusions. part marking information & packing : sop-8l 1.27 typ advanced power electronics corp. c detail a a1 a 1720 m ywwsss package code part numbe r detail a l date code (ywwsss) y last digit of the year ww week sss sequence e b 1 34 5 6 7 8 2 d e1 e
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