The TPS2340A contains main supply power control, auxiliary supply power control, power FETs for 12 V, -12 V and auxiliary 3.3 V supplies, and a serial interface for communications with and control of slots. Each TPS2340A contains supply control and switching for two slots. The main power control circuits start with all supplies off and hold all supplies off until power to the TPS2340A is valid on all positive supplies. When power is requested via the serial interface, the control circuit applies constant current to the