Power-on reset circuit for dual-supply system

摘要

A power-on reset circuit for a dual-supply system. The reset circuit includes a voltage divider powered by the first power supply and a sub-circuit supplied by the second power supply. The output of the voltage divider is connected to a control node of the first reset sub-circuit that is otherwise powered by the second power supply. A second reset sub-circuit is strictly regulated and powered by the second power supply. The first reset sub-circuit provides for translation of a signal having a potential limited by the potential of the first supply into a signal having a potential associated with that of the second supply. Only when a control signal from the voltage divider reaches a certain potential, and the second power supply reaches a certain potential, is the first reset sub-circuit activated in a manner that results in a circuit output signaling both supplies are at a suitable potential. This is useful for hot insertion applications in dual-supply systems.