CMOS to GPI interface circuit
US4866308A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 1988 |
| Grant date | Sep 12, 1989 |
| Priority date | — |
| Expiry date | Apr 11, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/00361
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A high speed, high performance CMOS to GPI interface circuit is disclosed. The interface circuit contains an input stage, clamping circuitry, an output stage and feedback circuitry. The clamping circuitry clamps the voltage level presented to the output stage at a level below the power supply voltage when the input from the CMOS circuit is at a high logic level. As the voltage level of the signal presented to the CPI circuitry rises, feedback circuitry feeds this signal back to the clamping circuitry, which in turn decreases the voltage level presented to the output stage. This assures the signal presented to the GPI circuit falls within the specified voltage level from 1.51 and 2.2 volts. The feedback circuitry contains a single pole filter that filters out high frequency reflections presented to the feedback circuitry, and a slew rate limiter that slows the rise and fall of the voltage level presented to the output stage thereby reducing noise on the power supply and ground lines. The feedback circuitry uses bilateral (push-pull) gain techniques to control the voltage level presented to the output stage as the input signal from the CMOS circuit swings from low to high logic level…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.