Digital to analog converter with a reduced resistor count
US5940020A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 9, 1997 |
| Grant date | Aug 17, 1999 |
| Priority date | — |
| Expiry date | Oct 9, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/765
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
This invention describes a DAC requiring a substantially lower number of resistors for conversion of n+p digital bits. The conversion to an analog signal is done in two voltage dividers. The first voltage divider contains 2.sup.n resistors and is referenced to a voltage bias. The second voltage divider contains 2.sup.p resistors and is referenced to a current bias. The current bias is derived from a current mirror which references the current in the first voltage divider. The use of the current mirror allows all resistors in the DAC to be of the same value which in turn provides an implementation with better accuracy and resistor matching. The number of resistors required to make a conversion of a 12 bit digital signal is 272 where 8 bits are converted in the first voltage divider and 4 bits are converted in the second voltage divider.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.