Abstract: This application discusses, among other things, switch circuit apparatus having power down protection and not requiring power up sequencing. An apparatus embodiment can include a first supply node coupled to a first input of a level shifting circuit via a protection circuit, a second supply node coupled to a second input of the level shifting circuit via a single pull-up transistor, and a switch including a control input, a first node, and a second node controllably isolated from the first node, wherein the control input is coupled to the level shifting circuit. The first and second inputs of the level shifting circuit can be coupled via a rectifier, and the protection circuit can be configured to power the first and second supply nodes to controllably isolate the first and second nodes from each other when a voltage of one of the first or second nodes exceeds a threshold.

Abstract: A switch can be configured to receive a first signal at a first input and provide an output signal at an output, depending on a state of the switch. A switch state change can be delayed until an indication of a requested switch state different than a current switch state is received and the first signal reaches a threshold.