High accuracy digital to analog converter using parallel P and N type resistor ladders
US6975261B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 15, 2004 |
| Grant date | Dec 13, 2005 |
| Priority date | — |
| Expiry date | Nov 15, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/785
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A D/A converter including first and second R-R2 resistor ladders and a set of SPDT switches. The first R-2R resistor ladder includes N type resistors coupled between a common voltage node and an output voltage node and the second R-2R resistor ladder includes P type resistors coupled between the common and output voltage nodes. The R-2R resistor ladders have multiple common switch terminals, each coupling an N type 2R resistor to a corresponding P type 2R resistor. Each SPDT switch is responsive to a data bit for switching a common switch terminal between the common voltage and a reference voltage. Each N type resistor may be formed in a PWell coupled to the common (or more negative) voltage and each P type resistor may be formed in an NWell coupled to the reference (or more positive) voltage. The SPDT switches may be configured with equivalent switch path impedances.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.