advanced power electronics corp. features description output voltage : 3.3v, 5v, 12v and adjustable output voltage adjustable version output voltage range, 1.23v to 19.5v 150khz fixed switching frequency. voltage mode non-synchronous pwm control. thermal-shutdown and current-limit protection. on/off shutdown control input. short circuit protect(scp) operating voltage can be up to 22v output load current 2a so-8 package low power standby mode. built-in switching transistor on chip rohs compliant 1. adjustable output voltage version table 1 resistor select for output voltage setting data and specifications subject to change without notice 201207176 ape1701 typical application 1 150khz, 2a pwm buck dc/dc converter the ape1701 series are monolithic ic designed for a step-down dc/dc converter, and own the ability of driving a 2a 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 compensation makes feedback control having good line and load regulation without external design. regarding protected function, thermal shutdown is to prevent over temperature operating from damage, and current limit is against ove r current operating of the output switch. if current limit function occurs and vfb is down below 0.5v, the switching frequency will be reduced. the ape1701 series operates at a switching frequency of 150khz thus allow smaller sized filter components than what would be needed with lowe r frequency switching regulators. the output version included fixed 3.3v, 5v, 12v, and an adjustable type. the chips are available in a standard so-8 package. c2 0.1uf d1 b340a l1 33uh 1 2 c3 470uf c1 470uf u1 ape1701 vcc sw fb en vss vss vss vss vin=12v on/off c6 0.1uf r2 1.5k r1 4.7k vout=5.0v/2a v out = v fb (1 + r1/r2 ) v fb = 1.23v r2 = 0.47k ~ 2.6k v out r2 r1 1.5k 4.7k 1.8k 5.6k 1.5k 2.5k 1.8k 3.0k 2.5v 1.8k 1.8k 1.8v 1.8k 0.82k 5v 3.3v
advanced power electronics corp. 2. fixed output voltage version 3. adjustable output voltage version with delayed startup 4. inverting -5v regulator with delayed startup 2 typical application ape1701 c1 470uf vout=3.3v/2a vin=12v c2 0.1uf d1 b240a l1 33uh 1 2 c3 470uf u1 ape1701-33 1 2 3 4 5 6 7 8 vcc sw fb en vss vss vss vss c6 0.1uf c2 0.1uf d1 b240a l1 22uh 1 2 c3 470uf c1 470uf u1 ape1701 1 2 3 4 5 6 7 8 vcc sw fb en vss vss vss vss vout=2.5v/2a vin=12v on/off c6 0.1uf r2 1.2k r1 1.3k c4 0.1uf r3 100k v out = v fb (1 + r1/r2 ) v fb = 1.23v r2 = 0.47k ~ 2.6k in5400 220uf 0.1uf 3a/20v vin=5~20v ape1701-50 1 2 3 4 5 6 7 8 vcc sw fb en vss vss vss vss 100uf 0.1uf 100k 2a/30v 220uf 33uh 0.1uf vout -5v200ma
advanced power electronics corp. ape1701 absolute maximum ratings (at t a =25c) maximum supply voltage(v cc ) ------------------------- - +24v on/off pin input voltage(v en ) ----------------------- - -0.3v to v cc feedback pin voltage(v fb ) ----------------------------- - -0.3v to 16v output voltage to ground(v out ) ----------------------- - -0.8v power dissipation(p d ) ------------------------------------ - (t j -t a )/rth ja storage temperature range(t st ) --------------------- - -65c to 150c operating temperature range(t op ) ------------------ - -20c to 125c operating supply voltage(v op ) ------------------------- +4.5v to +22v thermal resistance from junction to case(rth jc ) 20c/w 60c/w note. rth ja is measured with the pcb copper area(need connect to vss pins) of approximately 1.5 in 2 (multi-layer). ordering / package information electrical specifications (unless otherwise specified, t a =25 o c, v cc =12v for 3.3v, 5v, adjustable version and v cc =18v for the 12v version. i load = 0.2a) parameter sym test condition min typ max units quiescent current i q v fb =12v force driver off - 4 8 ma feedback bias current i fb v fb =1.3v(adj version only) - -10 -50 na shutdown supply current i sd v en =5v, v cc =22v - 35 100 ua pear current, no outside circuit v fb =0v force driver on max. duty cycle (on) v fb =0v force driver on - 100 - % min. duty cycle (off) v fb =12v force driver off - 0 - % oscillation frequency f osc 127 150 173 khz oscillation frequency of short (adjustable) when v fb < 0.5v -50- khz circuit protect (fixed) when < v out x 40% -50- khz i out =2a, no outside circuit v fb =0v force driver on no outside circuit v fb =12v force driver on sw pin=-0.8v v cc =22v force driver off - -5 - ma current limit 3 thermal resistance from junction to ambient(rth ja ) a sw pin=0v i swl - f scp 2.4 - - i cl dc saturation voltage v sat - 1.2 - -200 ua v 1.4 sw en vcc fb vss vss vss vss 1 3 2 4 8 6 7 5 so-8 (top view) ape1701x - xx package type m : so-8 blank : adj 33 : 3.3v 50 : 5.0v 12 : 12v output voltage sw pin leakage current
advanced power electronics corp. ape1701 electrical specifications(cont.) parameter sym test condition min typ max units v il low (regulator on) - 0.6 v v ih high (regulator off) 2 - v i h v en =2.5v(off) - -0.1 -0.5 ua i l v en =0.5v(on) - - -0.01 ua thermal shutdown temp. tsd - 135 - c version characteristics symbol conditions min typ max units i load =0.2a v out programmed for 3.3v v cc =12v, i load =2a -79- % v cc =12v, i load =2a -80- % v cc =12v, i load =2a -84- % v cc =15v, i load =2a - 90 - % pin descriptions pin symbol pin description v ss gnd pin fb control voltage feedback control en on/off shutdown sw switching output v cc ic power supply pin ape1701-12v en pin logic input threshold voltage en pin input current 1.3 ape1701-3.3v v out 3.2 v fb ape1701-adj 1.193 v 4 3.4 1.23 1.267 v 5.15 v ape1701-5.0v v out 4.85 5.0 i load =0.2a i load =0.2a 3.3 v v out 11.64 12 12.36 i load =0.2a output feedback voltage efficiency efficiency output voltage efficiency output voltage efficiency output voltage
advanced power electronics corp. ape1701 block diagram function description vcc vss sw feedback en 5 this is the positive input supply for the ic switching regulator. a suitable input bypass capacito r must be presented at this pin to minimize voltage transients and to supply the switching currents needed by the regulator. circuit ground. internal switch. the voltage at this pin switches between (+vcc ? vsat) and approximately ? 0.5v, with a duty cycle of approximately vout / vcc. to minimize coupling to sensitive circuitry, the pc board copper area connected to this pin should be minimized. senses the regulated output voltage to complete the feedback loop. 150khz osc. start up + + _ + _ thermal shutdown control + driver comp. comp. vss sw en fb 200mv 220mv switch _ comp. v cc current limit + _ amp comp. current source bias 1.235v reference 2.5v regulator r2 r1 adj : r2=0 , r1=open allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 100ua. pulling this pin below a threshold voltage o f approximately 1.3v turns the regulator on, and pulling this pin above 1.3v (up to a maximum of v cc ) shuts the regulator down. if this shutdown feature is not needed, the en pin can be wired to the ground p in.
advanced power electronics corp. ape1701 function description thermal considerations 6 the so-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 ape1701 j unction temperature rises above ambient temperature for a 2a load and different input and output voltages. the data for these curves was taken with the ape1701 (so-8 package) operating as a buck- switching regulator in an ambient temperature of 25 o c (still air). these temperature increments are all approximate and are affected by many factors. higher ambient temperatures requires more heat sinker. for the best thermal performance, wide copper traces and generous amounts of printed circuit board copper (need connect to the v ss pins) should be used in the board layout, (one exception is the sw(switch) pin, which should not have large areas of copper.) large areas of copper provide the best transfer of heat (lower thermal resistance) to the surrounding air, and moving air lowers the thermal resistance even further. package thermal resistance and junction temperature increments are all approximate. the increments are affected by a lot of factors. some of these factors include board size, shape, thickness, position, location, and even board temperature. other factors are, trace width, total printed circuit copper area, copper thickness, single or double-sided, multi-layer board and the amount of solder on the board. the effectiveness of the pc board to dissipate heat also depends on the size, quantity and spacing of other components on the board, as well as whether the surrounding air is still or moving. furthermore, some of these components such as the catch diode will add heat to the pc board and the heat can vary as the input voltage changes. for the inductor, depending on the physical size, type o f core material and the dc resistance, it could either act as a heat sink taking heat away from the board, or it could add heat to the board.
advanced power electronics corp. ape1701 typical performance characteristics 7 vou t vs vin 3.15 3.20 3.25 3.30 3.35 3.40 3.45 4 6 8 1012141618202224 vin(v) vout(v) iccq vs vin 0.00 1.00 2.00 3.00 4.00 5.00 6.00 4 6 8 1012141618202224 vi n (v) iccq(ma) fos c vs vin 140 145 150 155 160 165 170 4 6 8 1012141618202224 vi n (v) fosc(khz) fosc vs temp 120 130 140 150 160 170 180 -20 0 20 40 60 80 100 120 temp ( ) fosc (khz) vfb vs temp 1.18 1.20 1.22 1.24 1.26 1.28 -20 0 20 40 60 80 100 120 temp ( ) vfb (v) iccq vs temp 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)
advanced power electronics corp. ape1701 typical performance characteristics (v in =12v, v out =3.3v) (v in =12v, v out =5.0v) efficiency load transient response en on test wave (v in =12v, v out =5v, i out =0.1~2a) (v in =12v, v out =5v, i out =2a ) output ripple power on test wave (v in =12v, v out =3.3v, i out =2a) (v in =12v, v out =5v, i out =2a ) 8 efficiency vi n =1 2 v 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 0.0 0.5 1.0 1.5 2.0 iout(a) efficiency(%) vin=12v 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 0.0 0.5 1.0 1.5 2.0 iout(a) efficiency(%)
advanced power electronics corp. ape1701 marking information so-8 9 1701m-&& ywwsss part number package code output voltage : blank : adj ; 50 : 5.0v 33 : 3.3v ; 12 : 12v date code (ywwsss) y last digit of the year ww week sss sequence
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