A power sequencer controls the order in which voltage is applied to and disconnected from the power rails of a system. Power sequencing is a controlled process with defined time intervals between each rail for both power-up and power-down.
Power sequencing is an essential part of any design, especially in complex systems that utilize multiple power rails. For example, in AV systems, sequenced powering is often necessary to allow turn-on transients from low-level amplifiers and processors to settle down before any power amps are turned on.
A basic, cost-effective way to implement sequencing is to cascade the power good (PG) pin of one power supply into the enable (EN) pin of the next sequential supply. The second supply begins to turn on when the PG threshold is met, usually when the supply is at 90% of its final value.
Some power sequencers include:
Online & PA Sales
Contact our sales team