Overvoltage/undervoltage tolerant transfer gate
US6163199A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1999 |
| Grant date | Dec 19, 2000 |
| Priority date | — |
| Expiry date | Jan 29, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/0018
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A transfer gate or pass gate circuit for transferring logic signals between nodes for a range of available high-potential supply levels. The primary transfer gate is designed to protect against potentials that either exceed either a high-potential or a low-potential level or that undershoot such potential levels. For overshoot (overvoltage) tolerance, this is achieved by coupling a NMOS transistor in parallel with a pair of PMOS transistors that are coupled in series. All three transistors are located between two nodes, either of which can be the input or the output of the transfer gate. The NMOS transistor is designed to be larger than the PMOS transistors and carries most of the transfer capability. The smaller PMOS transistors are designed to eliminate potential drops that would otherwise occur with a single NMOS transistor or with a complementary pair of transistors. For undershoot (undervoltage) tolerance, a PMOS transistor is coupled in parallel with a pair of NMOS transistors that are coupled in series.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.