Compensated MOS string and DAC employing such a potentiometric string
US5943000A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 1997 |
| Grant date | Aug 24, 1999 |
| Priority date | — |
| Expiry date | Oct 22, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/765
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digital-to-analog converter includes a potentiometric string suitable for realizing a relatively high number of bits that significantly reduces the silicon area requirement and simplifies mismatch compensation. The structure includes a first resistance string to realize a first DAC to convert a first number of most significative bits, and a second potentiometric string functionally connected in cascade to the first, but realized with MOS transistors. The structure of the invention allows the coupling of the two DACs in cascade by exploiting the MOS transistors that form the second potentiometric string, that is, the second DAC, thus avoiding the use of operational switches or amplifiers which may provide error sources. Moreover, the structure of the invention lends itself to the implementation of efficient compensation circuits for integral and differential linearity errors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.