Patent · US Expired

CMOS power-on reset circuit

US5039875A · kind A · utility

53Cited by
4References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 28, 1989
Grant dateAug 13, 1991
Priority date
Expiry dateNov 28, 2009

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K17/223
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A power-on reset circuit. The reset circuit provides an automatic reset pulse immediately after power-up. The supply voltage is provided to the reset circuit. An RC filter with a variable time constant provides a "hump" waveform which is coupled to a waveform shaper. The waveform shaper converts the hump voltage output from the RC filter into a reset signal. Latching mechanisms are included to prevent refiring of the reset signal.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.