Patent · US Expired

5 Volt tolerant 3.3 volt output buffer

US5721508A · kind A · utility

27Cited by
2References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 24, 1996
Grant dateFeb 24, 1998
Priority date
Expiry dateJan 24, 2016

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K17/08142
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

Circuit for preventing the improper functioning of a CMOS output buffer that may occur due to the fact that since the output buffer P-channel may be coupled between a supply voltage and an output pad. If the pad is driven higher than the supply voltage by an external source, current may be injected into the parasitic diodes of the source/drain of the transistor.

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