Analog to digital converter having a magnitude amplifier with an improved differential input amplifier
US5554943A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 1, 1994 |
| Grant date | Sep 10, 1996 |
| Priority date | — |
| Expiry date | Dec 1, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45722
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved magnitude amplifier (magamp) is provided for a serial-type A/D converter. The magamp includes an improved differential input amplifier circuit to which offset circuitry is connected. These elements may be implemented in a single integrated circuit chip or as separate discrete circuits in hardware. The differential input amplifier circuit includes two pairs of differential input transistors, a comparator, and current switching control transistors. The comparator provides outputs that drive the current switching control transistors. The current switching control transistors are connected below the input transistors and not above the input transistors to reduce the parasitic capacitive loading at the outputs of the differential input amplifier circuit and increase the speed of the magamp. The offset circuitry provides the appropriate signals for aligning the output signals for output to the next stage magamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.