Power loss protection integrated circuit with autonomous capacitor health check

Abstract

A power loss protection integrated circuit includes a storage capacitor terminal (STR), an autonomous capacitor health check circuit, and a capacitor fault terminal (CF). The capacitor health check circuit autonomously performs periodic capacitor check operations. In a check operation, current is sinked from the STR terminal for a predetermined time and in a predetermined way. If during this time the voltage on the STR terminal STR drops below a predetermined voltage, then a digital signal CF is asserted onto the CF terminal. Immediately following each capacitor check, a charging voltage is driven onto the STR terminal to recharge the external capacitors coupled to the STR terminal. In one example, the integrated circuit further includes a current switch circuit (eFuse) and a buck/boost controller. The capacitor health check circuit is only enabled during normal mode operation of the integrated circuit, and the check circuit disables boost operation during capacitor checks.

Dependencies are inferred from the claim text.