ver: 0.1 feb 01, 2011 tel: 886-3-5788833 http://www.gmt.com.tw 1 G557 global mixed-mode technology inc. power distribution switch features ? 70m high-side mosfet (G557a,G557b,G557c) ? available with 3 versions of current limits with foldback ? operating range:2.7v to 5.5v ? 1.5ms typical rise time ? fast overcurrent response - 3s (typical) ? under voltage lockout ? 100 a quiescent supply current ? 1 a maximum shutdown supply current ? logic level enable pin, available with active-high or active-low version ? no reverse current when power off ? deglitched open-drain over-current flag output ( oc ) ? with output shutdown pull-low resister ? sop-8 ,msop-8,tdfn3x3-8 packages applications ? high-side power protection switch ? usb power management ? usb host and self-powered bubs ? usb bus-powered hubs ? hot plug-in power supplies ? battery-charger circuits general description the G557 is an integrated power switch for self-powered and bus-powered universal serial bus (usb) applications. G557a, G557b, G557c are 70m r ds(on) . several protection features include current limiting with foldback, and thermal shutdown to prevent catas- trophic switch failure caused by increasing power dis- sipation when continuous heavy loads or short circuit occurs. a built-in charge pump is used to drive the n-channel mosfet that is free of parasitic body diode to eliminate any reversed current flow across the switch when it is powered off. oc is open-drain output report over-current or over-temperature event and has typical 9ms deglitch timeout period. pin configuration typical application circuit 0.1 f 22 f load oc en(en) 1 f power supply 2.7v to 5.5v out in on off tdfn3x3-8 note: recommend connecting the thermal pad to the gnd for excellent power dissipation. G557 * * : 1 f of input capacitor is enough in most application cases. if the pcb trace of power rail to in is long, larger input capacitor is necessary. G557 8 6 5 1 2 3 4 gnd sop-8/msop-8 G557 7 out en (en) out oc in in out * 1 2 3 4 8 7 6 5 gnd in thermal pad in en (en) out out oc out * * pin#6 should be considered as out when circuit design and pcb layout, but it is nc pin actually. 0.1 f 22 f load oc en(en) 1 f power supply 2.7v to 5.5v out in on off tdfn3x3-8 note: recommend connecting the thermal pad to the gnd for excellent power dissipation. G557 * * : 1 f of input capacitor is enough in most application cases. if the pcb trace of power rail to in is long, larger input capacitor is necessary. G557 8 6 5 1 2 3 4 gnd sop-8/msop-8 G557 7 out en (en) out oc in in out * 1 2 3 4 8 7 6 5 gnd in thermal pad in en (en) out out oc out * 1 2 3 4 8 7 6 5 gnd in thermal pad in en (en) out out oc out * * pin#6 should be considered as out when circuit design and pcb layout, but it is nc pin actually.
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