Apparatus and method for a programmable trip point in an I/O circuit using a pre-driver
US6970015B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2002 |
| Grant date | Nov 29, 2005 |
| Priority date | — |
| Expiry date | Sep 13, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/0027
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention enables the performance of the input and output stages of an I/O circuit to be modified after an IC is manufactured. In one embodiment, the I/O circuit includes an output driver, programmable pre-driver, programmable Schmitt-trigger input buffer, control circuit and logic circuit. Depending on the number of pull-up and pull-down MOS transistor pairs or “cells” that are enabled in the programmable pre-driver and their different sizes, the overall sizing ratio imbalance between the transistors may be programmed. In particular, the high and low trip points for activation of the output driver is related to an imbalance in the overall sizing ratio of transistors enabled in the programmable pre-driver. This affects the timing characteristics of the output driver.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.