Rail-to-rail DAC drive circuit
USRE38083E1 · kind E1 · reissue
Assignee
Inventor
Key dates
| Filing date | Nov 4, 1999 |
| Grant date | Apr 22, 2003 |
| Priority date | — |
| Expiry date | Nov 4, 2019 |
Classification
- Technology area (CPC —)General
Abstract
A voltage mode digital-to-analog converter (DAC) with an output buffer operational amplifier is provided with a rail-to-rail output voltage capability by reducing the DAC's output voltage swing to a range that is within the amplifier's permissible input signal range, and connecting the amplifier in a multiplier configuration to produce a corresponding multiplication of its input signal. The DAC output reduction is preferably achieved by delivering an n-bit input digital signal to an n+m bit DAC, and holding the DAC's m most significant bits OFF. The m most significant bits are dummy bits that are impedance matched with the DAC, while the amplifier is an operational amplifier with a feedback circuit that is also impedance matched to the DAC.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.