Patent · US Expired

Circuit for auto-clamping input pins to a definite voltage during power-up or reset

US6998884B2 · kind B2 · utility

5Cited by
8References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 31, 2003
Grant dateFeb 14, 2006
Priority date
Expiry dateDec 31, 2023

Classification

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

Abstract

An auto-grounding circuit responsive to a reset signal discharges an input terminal of an integrated circuit and its associated input line to ground, using a pull-down transistor coupled to the input line, with a gate of the pull-down transistor coupled to receive the reset signal. An exemplary circuit also includes a NAND gate and a second pull-down transistor to maintain an established voltage level of the input line after the reset signal is no longer asserted until the input terminal is driven by an applied input signal. The voltage maintaining circuitry is weaker than the main pull-down transistor to avoid interfering with normal operation of the input terminal.

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