Power Supply Sequencer and Monitor with Non-Volatile Error Logging

The UCD9081 power-supply sequencer controls the enable sequence of up to eight independent voltage rails and provides four general-purpose digital outputs (GPO). The device operates from a 3.3-V supply, provides 3.2-mV resolution of voltage rails, and requires no external memory or clock. The UCD9081 monitors the voltage rails independently and has a high degree of rail sequence and alarm response options. The sequencing of rails can be based on timed events or on timed events in conjunction with other rails achieving regulation or a voltage threshold. In addition, each rail is monitored for undervoltage and overvoltage glitches and thresholds. Each rail the UCD9081 monitors can be configured to shut down a user-defined set of other rails and GPOs, and alarm conditions are monitored on a per-rail basis.