USB Power Switches

The universal serial bus (USB) protocol defines several classes of devices, each with their unique power requirements.  A USB power switch is a component that supervises the power levels for one or more devices on a USB interface.  They can monitor current, voltage and temperature levels and disengage a load from the power bus if any of these levels are out of range.  Often, these chips will have built-in timers and slew rate controllers in order to ensure safe transitions between power on and power off states.  Some USB power switches may have advanced control features that provide the proper signaling protocols on the data pins to enable charging a device over a USB interface.