Variable pulse PWM DAC method and apparatus
US6362766B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 2000 |
| Grant date | Mar 26, 2002 |
| Priority date | — |
| Expiry date | Feb 9, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/822
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A variable pulse pulse width modulation digital-to-analog converter comprising: an input code register to store a digital input code to be converted; a PWM decoder, coupled to the input code register, to convert the input code to a series of pulses; an output driver circuit coupled to the PWM decoder, wherein the output driver circuit generates an output signal comprising pulses of a high logic level and pulses of an intermediate logic level; and a filter to integrate the pulses to generate an analog output value corresponding to the digital input code. In one embodiment, the output stage comprises an active tri-state driver, a multiplexer and at least two output reference voltage sources. Using a plurality of different amplitude pulse levels enables PWM DACs according to the present invention to provide greater resolution than conventional PWM DACs for a given clock frequency and conversion period.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.