Digital to analog converter with dual resistor string
US5703588A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1996 |
| Grant date | Dec 30, 1997 |
| Priority date | — |
| Expiry date | Oct 15, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/365
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a dual resistor string digital-to-analog converter, current biasing is used to isolate a first resistor string from a second resistor string. The first resistor string consist of multiple first resistors, and a first switch network responsive to the MSBs selectively couples the second resistor string in parallel to any one first resistor within the first resistor string. To prevent the second resistor string from drawing current from the first resistor string, a current source feeds a bias current into the second resistor string and a current drain draws the bias current from the second resistor string. The bias current is adjusted such that the voltage drop across the whole of the second resistor string is equal to the voltage drop across any one first resistor within the first resistor string. Use of a current source and current drain allows one to freely adjust the number of MSBs, LSBs and first and second resistor magnitudes to obtain optimum performance without concern for any adverse nonlinearity effects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.