Wake-up reset circuit

Abstract

A wake-up reset circuit is provided that generates a reset signal to a digital circuit upon a wake-up event. The wake-up reset circuit places the digital circuit into a known reset condition upon wake-up, even if a brown out condition occurs which may have caused unstable and unknown logic states in sequential circuit elements, e.g., volatile memory, flip flops and / or latching circuits. The wake-up reset circuit draws substantially no current when not generating the reset signal.

Description

[0001] This application is a divisional application of an invention patent application with an application date of December 15, 2004, an application number of 200480038165.2, and an invention title of "wake-up and reset circuit". technical field [0002] The present invention basically relates to digital electronic circuits. More particularly, the present invention relates to wake-up reset circuits that generate an integrated circuit ("chip") reset after a wake-up event occurs. Background technique [0003] Electronic circuits have been used to monitor power supply voltages of electronic components in order to detect voltage thresholds required to generate a power-on reset ("POR") for the electronic components. The same or other circuits have been used to detect brownout or brownout conditions. Typically POR and brownout detection circuits always require quiescent current to function. For electronic components that rely on batteries, especially for components that are expe...

AI Technical Summary

Problems solved by technology

For electronic components that rely on batteries, especially for components that are expected to operate for a long time, this quiescent current is an important factor in reducing the life of the battery

Other issues inherent to POR and / or brownout circuits are proper operation when power supplies are below critical voltages, making digital logic circuits in unpredictable "sub-stable" states and when applied in electrically noisy environments

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