TTL-to-CMOS buffer
US4763022A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 5, 1987 |
| Grant date | Aug 9, 1988 |
| Priority date | — |
| Expiry date | Jan 5, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/018521
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A TTL-to-CMOS converter consists of a plurality of N-channel and P-channel MOS transistors, each of which is fabricated so as to have a predetermined channel Width-to-Length ratio (W/L). The transistors are arranged to include an input complementary pair for accepting TTL-level signals and an output complementary pair for providing CMOS-level signals. An N-channel tracking transistor is coupled between the drain electrodes of the P-channel and N-channel transistors of the input complementary pair. The (W/L) of the tracking transistor is approximately 1/8 to to 1/7 times the (W/L) of the N-channel transistor of the input complementary pair. This arrangement establishes a converter switch point with a significantly greater degree of accuracy than otherwise attainable. A pull-up transistor has a gate electrode coupled to the input terminal of the input complementary pair and a drain electrode coupled to the input electrode of the output complementary pair. The pull-up transistor operates to pull the input terminal of the output complementary pair toward Vdd as the TTL logic level at the input of the Buffer goes low.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.