Output buffer with protective limit of voltage across terminals of devices within the output buffer
US6081152A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 2, 1998 |
| Grant date | Jun 27, 2000 |
| Priority date | — |
| Expiry date | Oct 2, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An output buffer interfaces a digital system having devices designed for low operating voltages to an output coupled to an external system having higher operating voltages. The output buffer drives the output to one of a high output voltage and a low output voltage while limiting voltage across terminals of devices within the output buffer. The output buffer includes a pull-up stack of a first plurality of devices, coupled between a high power supply and the output, which turn on when the output is driven to the high output voltage and which turn off when the output is driven to the low output voltage. The voltage difference between the output and the high power supply is distributed across the first plurality of devices when the output is driven to the low output voltage. The output buffer further includes a pull-down stack of a second plurality of devices, coupled between a low power supply and the output, which turn on when the output is driven to the low output voltage and which turn off when the output is driven to the high output voltage. The voltage difference between the output and the low power supply is distributed across the second plurality of devices when the output is…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.