The AAT4290 and AAT4291 SmartSwitch products are members of AnalogicTech's Application Specific Power MOSFETTM (ASPMTM) product family. The AAT4290 and AAT4291 are five and three P-channel MOSFETs, respectively, configured for use as a microprocessor I/O expander. Having independent drain outputs and a common source input, they operate with an input voltage ranging from 1.8V to 5.5V, making them ideal for 2.5V, 3.3V, or 5V systems, as well as systems powered by lithium-ion/polymer batteries. Each switch features a 500ns turn-on time. The switch states are controlled by AnalogicTech's Simple Serial ControlTM (S2CwireTM) interface which permits ease of control and efficiency of size. The quiescent supply current is very low, typically 5A. In shutdown mode, the supply current is reduced to less than 1A.