step-up dc/dc converter with accurate input current limit china resources powtech (shanghai) limited www.crpowtech.com page 1 pt1307_dsb rev en_1.4 pt1307 general description the pt1307 is a current mode dc-dc converter with accurate input current limit. it is suitable for use in topologies requiring low side mosfet, such as boost, fly-back or sepic. the pt1307 has built in fault condition protection features such as short-circuit protection, and thermal shut down protection. the pt1307 also has an ovlo function that locks out the switch when the input voltage is higher than 6.5v, although the, in, and cs can stand up to 20v. the pt1307 provides programm able average current limiting with 2% accuracy , which allows accurate limiting of the average current in the inductors, independent of peak current. the pt1307 is available in sot23-6. features z 2% programmable average current limiting z 1mhz switching frequency z short-circuit protection z ovlo with hysteresis applications z battery chargers z li-ion and usb powered systems z portable instruments z step-up dc-dc converters z step-up/step-down and isolated dc/dc converters ordering information package temperature range ordering part number transport media mark sot-23-6 -40c to 85c PT1307X23F tape and reel 3000 units acog note typical applications fig. 1
step-up dc/dc converter with accurate input current limit china resources powtech (shanghai) limited www.crpowtech.com page 2 pt1307_dsb rev en_1.4 pt1307 pin assignment pin descriptions pin no symbol function 1 comp compensation pin, an rc network connected to this pin provides compensation for the control loop 2 gnd ground pin 3 fb feedback pin, a portion of the output voltage is sensed at this pin 4 sw output for internal power switch 5 cs current sense pin, voltage generated across an external resister is fed into this pin 6 in power supply input pin absolute maximum ratings (note1) symbol description value units comp comp pin voltage -0.3~7 v vfb feedback pin voltage -0.3~7 v vsw sw pin input voltage -0.3~25 v isw sw pin output current 2 a vin supply voltage -0.3~25 v vcs cs pin input voltage -0.3~25 v p tr1 thermal resistance sot-23-6 ja jc 250 145 /w t j junction temperature 125 c t solder lead temperature (soldering, 10 sec) 260 c t opt operation temperature -40~+85 t stg storage temperature range -55~+125 recommended operating conditions (note2) symbol description value units vfb feedback pin voltage 0~5.5 v vin supply voltage 0~20 v vcs cs pin input voltage 0~20 v vsw sw pin input voltage 0~20 v isw sw pin output current 1.5 a comp gnd fb sw in cs acog
step-up dc/dc converter with accurate input current limit china resources powtech (shanghai) limited www.crpowtech.com page 3 pt1307_dsb rev en_1.4 pt1307 notes: 1. exceeding these ratings may damage the device 2. the device is not guaranteed to function outside of its operating rating simplified block diagram electrical characteristics (v in = 5v, ta = 25 , fig.1, unless otherwise specified.) symbol parameter conditions min typ max unit v in input voltage range 4.75 5.25 v i s input dc bias cu rrent no load 0.5 2 ma v ovlo input over voltage lockout threshold 6 6.5 7 v v ovlo input over voltage lockout threshold hysteresis 200 mv fs switching frequency 0.8 1 1.2 mhz i in input current limit r cs = 0.2 tsd thermal shut down hystersis i out = 0 20
step-up dc/dc converter with accurate input current limit china resources powtech (shanghai) limited www.crpowtech.com page 4 pt1307_dsb rev en_1.4 pt1307 package information sot23-6 package millimeter symbol min nom max a - - 1.30 a1 0.04 0.07 0.10 a2 1.00 1.10 1.20 a3 0.55 0.65 0.75 b 0.34 - 0.43 b1 0.33 0.35 0.38 c 0.15 - 0.21 c1 0.14 0.15 0.16 d 2.72 2.92 3.12 e 2.60 2.80 3.00 e1 1.40 1.60 1.80 e 0.95bsc l 0.30 - 0.60 0 - 8
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