The AT1605 is a smart high-side power switch to be able to supply up 2.0A from input source. The device features preventable reverse current flow from OUT to Input by free of parasitic body diode, when output voltage exceeds the input voltage, the N-MOS is turned off. The AT1605 includes built-in low on-resistance of NMOS to saved conductive loss, charge pump circuitry to drive N-MOS, built-in current limit, soft-start, thermal protection and under voltage lock function. Operating voltage range between 1.8V and 5.5V supports one Li-lon or adaptor source.