ver: 1.3 aug 24, 2009 tel: 886-3-5788833 http://www.gmt.com.tw 1 G551/g552 global mixed-mode technology inc. current-limit switches features ? 700m on-resistance ? 2 versions of current limits, 85ma (G551b1/ b2 & g552b1/b2) and 170ma (G551a1/a2 & g552a1/ a2) ? 2v to 5.5v supply range ? undervoltage lockout ? 85 a supply current ? 1 a maximum shutdown current ? auto-restart function (G551a1/b1 & g552a1/b1) or latch-off function (G551a2/b2 & g552a2/b2) ? active high enable (G551) or active low enable (g552) ? thermal-shutdown protection ? reverse-current limit protection ? 40ms blanking time ? 280ms auto-restart time (G551a1/b1 & g552a1/b1) ? fault flag function ? fast current-limit response time ? sc-70-5( sot-353) package applications ? pdas ? cell phones ? gps systems ? hand-held devices general description the G551/g552 family of switches feature internal cur- rent limiting to prevent host devices from being dam- aged due to faulty load conditions. these analog switches have a low 0.7 on-resistance and operate from a 2.0v to 5.5v input voltage range. they are available with guaranteed 50ma and 100ma current limits, making them ideal for load-switching applica- tions. when the switch is on and a load is connected to the port, a typical blanking time of 40ms ensures that the transient voltages settle down. if after this blanking time the load current is greater than the current limit, the G551a2/b2 & g552a2/b2 enter a latch-off state where the switch is turned off and flag is issued to the microprocessor. the switch can be turned on again by cycling the power or the on pin. the G551a1/b1 & g552a1/b1 have an auto-restart feature where the switch turns off after the blanking time and then continuously checks to see if the over- load condition is present. the switch remains on after the overload condition disappears. the on pin of G551 series are active high, while g552 series are active low. pin configuration typical application circuit on (on) sc-70-5 (sot-353) 5 vout 3 flag vin 4 2 1 gnd G551/g552 flag out vin on off gnd v out flag v in G551/g552 on (on) () is for g552 on (on) sc-70-5 (sot-353) 5 vout 3 flag vin 4 2 1 gnd G551/g552 flag out vin on off gnd v out flag v in G551/g552 on (on) () is for g552
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