www. belling .com .cn 1 1a usb load current switch with 5v output voltage limit BL2556 description the BL2556 is 1a usb load current s witch with output voltage limit at 5v, designed for high - side load switching applications. the internal current - limiting circuit protects the input supply against large output short circuit current which may cause the supply to fall out of regulation. the outp ut voltage limiting function protects the output over voltage when BL2556 s vin sees voltage surge. the current limit is fixed around 1. 4 a which allow 1a usb application. the quiescent supply current is typically 1 5 a, making the device ideal for portable battery - operated equipment. in shutdown mode, the supply current decreases to less than 0.1a. additional features include thermal shutdown and short - circuit protection and current fold - back . the part is available in a tiny sot23 - 5 package. features ? stand input voltage as high as 10 v ? o utput voltage limiting at 5v ? controlled turn - on ? f ixed current limit large than 1a ? 0. 25 ohm on resistance ? extremely low quiescent current at 15ua typ. ? logic control shutdown (iq<1ua) ? thermal shutdown ? short - circuit protection ? short - circuit current fold - back ? sot23 - 5 package applications ? portable devices ? mid, mp4 ? set top boxes ? notebook and pc mother board ? usb supplied devices typical application pin out & marking p0: product code; yw : data code ordering information bl2 556 v i n v o u t g n d 1 u f v i n 4 . 7 u f l c 4 0 0 1 c e v o u t c e 1 2 3 5 4 s o t 2 3 - 5 c e n c v i n v o u t g n d p 0 y w |
www. belling .com .cn 2 BL2556 part no. package tape&reel BL2556 cb5tr sot23 - 5 3000/reel absolute maximum rating parameter value max input voltage 10 v max operating junction temperature(tj) 1 25 ? c ambient temperature(ta) - 4 0 ? c C 85 ? c maximum power dissipation sot23 - 5 0.35 w storage temperature(ts) - 40 ? c - 150 ? c lead temperature & time 260 ? c , 10s esd (hbm) > 2 000v note: exceed these limits to damage to the device. exposure to absolute maximum rating conditions may affect device reliability. r ecommended work conditions parameter value input voltage range max. 5.5v operating junction t emperature(tj) - 20 ? c C 125 ? c electrical characteristics ( v in =5v, t a =25 ? c ) symbol parameter conditions min typ max unit v in input voltage range 1.5 5.5 v iq quiescent current active, vfb=0 .65 , no switching 15 50 ua shutdown 1 ua rdson switch rdson iout=500ma 250 350 mohm ilimit fixed current limit 1.5 a vovp output voltage limiting v in=6v 4.9 5 5 .1 v vh_ o n o n input high voltage 1.5 v vl_ o n o n input low voltage 0. 3 v tsd thermal shutdown temp. 1 6 5 o c
www. belling .com .cn 3 BL2556 pin description pin # name description 1 vout switch output, the output of power switch 2 gnd ground 3 nc not connected 4 ce control input, enable pin, active high 5 vin supply input voltage electrical performance tested under ta=25 ? c , cin=1uf, cout=1uf, unless otherwise specified block diagram
www. belling .com .cn 4 BL2556 detailed description operation the BL2556 is a current limited switch that protects systems and loads which can be damaged or disrupted by the application of high currents. the core of each device is a 0. 25 p - channel mosfet and a controller capable of functioning over a wide input oper ating range up to 10v . the chip protects against system malfunctions through current limiting, undervoltage lockout and thermal shutdown. the current limit is set around 1.5a a nd it offers an unique function to limit output voltage at 5v . on/off control the ce pin controls the state of the switch. w hen ce is high, the switch i s in the on state. activating ce continuously holds the switch in the on state so long as there is no fault. an under voltage on vin or a junction temperature in excess of 1 6 5c overrides the ce control to turn off the switch. output over - voltage limiting BL2556 provides an unique output voltage limiting function, to protect the load which follows it. when BL2556 find out input voltage higher than 5.3v, it will limit the output voltage, so the output will not exceed standard usb voltage even when input come s across a voltage surge. current limiting the current limit is internally set around 1.5a to ensure a 1a application. thermal and short circuit protection BL2556 will shut off its output when its temperature higher than 165 c (typical value) . and it has unique short circuit fold - back function to keep itself cold when output is shorted to gnd. package out line package sot23 - 5 devices per reel 3000 unit mm package specification:
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