Process insensitive off-chip driver
US5534803A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1995 |
| Grant date | Jul 9, 1996 |
| Priority date | — |
| Expiry date | Apr 12, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/00384
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A small and efficient control circuit for a compensated CMOS off-chip driver and a driver circuit incorporating the control circuit. The control circuit uses an exclusive OR gate as a phase detector to determine the phase difference between a system clock and a delayed version of the system clock. An RC filter smooths the output of the exclusive OR gate to produce a voltage proportional to the delay introduced in the CMOS circuitry by environmental and process variables. The voltage from the RC filter is used as a control voltage to control the effective channel width of the effective pull-down device of the off-chip driver circuit. An off-chip driver using the control circuit is used in the I/O unit of a CMOS integrated circuit chip.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.