Output buffer and method therefor
US6326811A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 2000 |
| Grant date | Dec 4, 2001 |
| Priority date | — |
| Expiry date | Sep 11, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/00315
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An output buffer (200) having a protection circuit (228, 230, 232) which adjusts control of an output drive circuit (224, 226) in response to external voltages on the output pin (202). When the output pin is in a tri-state condition and receives an external voltage which is outside a predetermined voltage range, the protection circuit adjusts the voltage on the control gate of a transistor (224) in the output drive circuit. The protection circuit maintains the voltage across the transistor within the tolerance of the transistor. In one embodiment, the output drive circuit has pullup (204) and pulldown (206) portions. The output buffer provides a high voltage output driver having low voltage devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.