Power sequencing

"Up-sequencing" and "Down-sequencing" redirect here. For unrelated but similar-sounding terms, see Up-cycling and Down-cycling.

Example power-up sequencing of three voltage sources

In electronic circuits that have multiple power supplies, power sequencing is the process of turning power supplies on or off in a particular order and in accordance with specific timing constraints, for the purpose of preventing conditions that could damage circuitry or cause improper operation.

In practice, a variety of methods are commonly used to control power sequencing. Such methods may incorporate fixed time delays, or use feedback from power supplies, or both to control power sequencing. Some power sequence controllers have fixed functionality, and others are programmable.