ap1507 150khz, 3a pwm buck dc/dc converter this datasheet contains new product information. anachip 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. rev. 0.2 jan 16, 2004 1/9 features - output voltage: 3.3v, 5v, 12v and adjustable output version - adjustable version output voltage range, 1.23v to 18v+ 4% - 150khz + 15% 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 22v - output load current: 3a - to252-5l packages - low power standby mode - built-in switching transistor on chip applications - simple high-efficiency step-down regulator - on-card switching regulators - positive to negative converter general description the ap1507 series are monolithic ic designed for a step-down dc/dc co nverter, and ow n the ability of driving a 3a load without external transistor. due to reducing the number of external component, the board space can be saved easily. the external shutdown function can be controlled by logic level and then come into standby mode. the internal compensation makes feedback control have 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 over current operating of the output switch. if current limit function occurred and v fb is down to 0.5v below, the switching frequency will be reduce d. the ap1507 series operates at a switching frequency of 150khz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. other features include a guaranteed + 4% tolerance on output voltage under specified input voltage and output load conditions, and + 15% on the oscillator frequen cy. the output version included fixed 3.3v, 5v, 12v, and an adjustable type. the package is available in a 5-lead to-252. pin assignments ( top view ) to252-5l 5 sd 4 fb 3 gnd 2 output metal tab gnd 1 v in pin descriptions name description v in operating voltage input output switching output gnd ground fb output voltage feedback control sd on /off shutdown
ap1507 150khz, 3a pwm buck dc/dc converter anachip corp. www.anachip.com.tw rev. 0.2 jan 16, 2004 2/9 ordering information package d5: to252-5l output version ap1507 xx x x x packing blank : tube a : taping blank : adjustable -33 : 3.3v -50 : 5.0v -12 : 12v lead free blank : normal l : lead free package block diagram current source bias 1.235v reference 2.5v regulator 150khz osc. start up + + _ + _ thermal limit pre-driver comp comp gnd output v in sd fb 220mv 200mv 3a switch + _ _ amp comp frequecy compen- sation
ap1507 150khz, 3a pwm buck dc/dc converter anachip corp. www.anachip.com.tw rev. 0.2 j an 16, 2004 3/9 absolute maximum ratings symbol parameter rating unit v cc supply voltage +24 v v sd on /off pin input volta g e -0.3 to +18 v v fb feedback pin voltage -0.3 to +18 v v out output voltage to ground -1 v p d power dissipation internally limited w t st storage temperature -65 to +150 o c t op operating temperature -40 to +125 o c v op operating voltage +4.5 to +22 v electrical characteristics (a ll output voltage versions) unless otherwise specified, v in =12v for 3.3v, 5v, adjustable version and v in =18v for the 12v version. i load = 0.5a symbol parameter conditions min. typ. max. unit -50 i b feedback bias current v fb =1.3v (adjustable version only) -10 -100 na 127 150 173 f osc oscillator frequency 110 173 khz f scp oscillator frequency of short circuit protect when current limit occurred and v fb < 0.5v, ta=25 o c 5 15 25 khz 1.6 v sat saturation voltage i out =3a no outside circuit v fb =0v force driver on 1.4 1.7 v max. duty cycle (on) v fb =0v force driver on 100 dc min. duty cycle (off) v fb =12v force driver off 0 % 5.5 i cl current limit peak current no outside circuit v fb =0v force driver on 3.6 4.5 6.5 a output = 0v no outside circuit v fb =12v force driver off -200 ua i leak output = -1v output leakage current v in =22v -5 ma i q quiescent current v fb =12v force driver off 5 10 ma 150 i stby standby quiescent current on /off pin=5v v in =22v 70 200 ua v il low (regulator on) - 0.6 v ih on /off pin logic input threshold voltage high (regulator off) 2.0 1.3 - v i h on /off pin logic input current v logic =2.5v (off) -0.01 i l on /off pin input current v logic =0.5v (on) -0.1 -1 ua jc thermal resistance to252-5l junction to case 10 o c/w ja thermal resistance with copper area of approximately 2cm 2cm to252-5l junction to ambient 50 o c/w specifications with boldface type are for full operating temperature range, the other type are for t j =25oc.
ap1507 150khz, 3a pwm buck dc/dc converter anachip corp. www.anachip.com.tw rev. 0.2 j an 16, 2004 4/9 electrical characteristics (continued) symbol parameter conditions typ. limit unit fb v output feedback 5v < v in < 22v 0.2a < i load < 3a v out programmed for 3v 1.23 1.193/ 1.18 1.267/ 1.28 v v min v max ap1507-adj efficiency v in = 12v, i load =3a 74 % out v output voltage 5.5v < v in < 22v 0.2a < i load < 3a 3.3 3.168/ 3.135 3.432/ 3.465 v v min v max ap1507-3.3v efficiency v in = 12v, i load =3a 75 % out v output voltage 8v < v in < 22v 0.2a < i load < 3a 5 4.8/ 4.75 5.2/ 5.25 v v min v max ap1507-5v efficiency v in = 12v, i load =3a 80 % out v output voltage 15v < v in < 22v 0.2a < i load < 3a 12 11.52/ 11.4 12.48/ 12.6 v v min v max ap1507-12v efficiency v in = 16v, i load = 3a 89 % specifications with boldface type are for full operating temperature range, the other type are for t j =25oc.
ap1507 150khz, 3a pwm buck dc/dc converter anachip corp. www.anachip.com.tw rev. 0.2 j an 16, 2004 5/9 typical performance characteristics ap1507 efficiency v.s. temperature (vin=12v,vout=5v,io=3a) 72 73 74 75 76 77 78 79 80 81 82 83 -50 -30 -10 10 30 50 70 90 110 130 150 temperature (ta) (c) efficiency (%) ap1507 efficiency v.s. temperature (vin=12v,vout=3.3v,io=3a) 70 71 72 73 74 75 76 77 78 -50 -30 -10 10 30 50 70 90 110 130 150 temperature (ta) (c) efficiency (%) ap1507 saturation voltage v.s. temperature (vcc=12v,vfb=0v,vsd=0) 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 -50 -25 0 25 50 75 100 125 temperature (ta) (c) saturation voltage (v) 3a 2a 1a 0.5a ap1507 switch current limit v.s. temperature (vcc=12v,vfb=0v) 3 3.5 4 4.5 5 5.5 -50 -30 -10 10 30 50 70 90 temperature (ta) (c) switch current limit (a) ap1507 supply current v.s. temperature (vcc=12v , no load ,von/off =0v(swit ch on) ,von/off =5v(switch off)) 5 6 7 8 9 10 11 12 13 14 15 -50 -30 -10 10 30 50 70 90 110 130 150 temperature (ta) (c) supply current (ma) switch on 30 35 40 45 50 55 60 -50 -30 -10 10 30 50 70 90 110 130 150 temperature (ta) (c) supply current (ua) switch off
ap1507 150khz, 3a pwm buck dc/dc converter anachip corp. www.anachip.com.tw rev. 0.2 j an 16, 2004 6/9 typical performance char acteristics (continued) ap1507 threshold voltage v.s. temperature (vcc=12v , io=100ma) 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 -50 -30 -10 10 30 50 70 90 110 130 150 temperature (ta) (c) threshold voltage (v) ap1507 on/off current v.s. on/off voltage (vin=12v) -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 0 3 6 9 12 15 18 21 on/off voltage (v) on/off current (na) ap1507 frequency v.s. temperature (vcc=12v , io=500ma ,vout=5v) 140 145 150 155 160 165 170 -50-30-101030507090110130150 temperature (ta) (c) frequency (khz) ap1507 feedback curr ent v.s. temperature (vcc=12v , vout=5v,vfb=1.3v) -50 -40 -30 -20 -10 0 10 -50 -30 -10 10 30 50 70 90 110 130 150 temperature (ta) (c) feedback current (na) ap1507 output voltage v.s. temperature (vin=12v ,io=3a) 2.9 2.95 3 3.05 3.1 3.15 3.2 3.25 3.3 3.35 3.4 3.45 3.5 -40-20 0 20406080100120140160 temperature (ta) (c) vout (v)
ap1507 150khz, 3a pwm buck dc/dc converter anachip corp. www.anachip.com.tw rev. 0.2 j an 16, 2004 7/9 typical application circuit 12 3 5 4 12v dc input c in capacitor fb sd d1 schottky diode vin gnd output ap1507 -33 co capacitor inductor l1 3.3v/3a output load function description pin functions +v in this is the positive input supply for the ic switching regulator. a suitable input bypass capacitor must be present at this pin to minimize voltage transients and to supply the switching currents needed by the regulator. ground circuit ground. output internal switch. the voltage at this pin switches between (+v in ? v sat ) and approximately ? 0.5v, with a duty cycle of approximately v out / v in . to minimize coupling to sensitive circuitry, the pc board copper area connected to this pin should be kept a minimum. feedback (fb) senses the regulated output voltage to complete the feedback loop. on /off (sd) allows the switching re gulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 150ua. pulling this pin belo w a threshold voltage of approximately 1.3v turns the regulator on, and pulling this pin above 1.3v (up to a maximum of 18v) shuts the regulator down. if this shutdown feature is not needed, the on /off pin can be wired to the ground pin or it can be left open, in either case the regulator will be in the on condition. thermal considerations the to-252 surface mount package tab is designed to be soldering to the copper on a printed circuit board. the copper and the board are the heat sink for this package and the other heat producing components, such as the catch diode and inductor. the pc board copper area that the package is soldered to should be at least 0.8 in 2 , and ideally should have 2 or more square inches of 2 oz. additional copper area improves the thermal characteristics, but with copper areas greater than approximately 6 in 2 , only small improvements in heat dissipation are realized. if further thermal improvements are needed, double sided, multi-layer pc board with large copper areas and/or airflow will be recommended.
ap1507 150khz, 3a pwm buck dc/dc converter anachip corp. www.anachip.com.tw rev. 0.2 j an 16, 2004 8/9 function description (continued) the ap1507 (to-252 package) junction temperature rises above ambient temperature with a 3a load for various input and output voltages. this data was taken with the circuit operating as a buck-switching regulator with all components mounted on a pc board to simulate the junction temperature under actual operating conditions. this curve can be used for a quick check for the approximate junction temperature for various conditions, but be aware that there are many factors that can affect the junction temperature. when load currents higher than 3a are used, double sided or multi-layer pc boards with large copper areas and/or airflow might be needed, especially for high ambient temperatures and high output voltages. for the best thermal performance, wide copper traces and generous amounts of printed circuit board copper should be used in the board layout. (once exception to this is the output (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 rise numbers are all approximate, and there are many factors that will affect these numbers. 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 of 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. marking information to252-5l ac 1507 - xx logo id code xth week: 01~52 year: (top view) "02" = 2002 "01" = 2001 x x x x x x ~ part number output type: blank: adjustable 33: 3.3v 50: 5.0v 12: 12v blank: normal l: lead free package
ap1507 150khz, 3a pwm buck dc/dc converter anachip corp. www.anachip.com.tw rev. 0.2 jan 16, 2004 9/9 package information package type: to252-5l a b m c d s g p(typ.) h j l k dimensions in millimeters dimensions in inches symbol min. nom. max. min. nom. max. a 6.35 6.60 6.85 0.250 0.260 0.270 b 5.20 5.35 5.50 0.205 0.211 0.217 c 6.80 7.00 7.20 0.268 0.276 0.283 d 2.20 2.50 2.80 0. 087 0.098 0.110 p 1.27 ref. 0.050 ref. s 0.50 0.65 0.80 0. 020 0.026 0.031 g 0.40 0.50 0.60 0.016 0.020 0.024 h 2.20 2.30 2.40 0.087 0.091 0.094 j 0.46 0.52 0.58 0. 018 0.020 0.023 k 0.00 0.08 0.15 0.000 0.003 0.006 l 0.90 1.20 1.50 0. 035 0.047 0.059 m 5.40 5.50 5.59 0. 213 0.216 0.220
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