Patent · US Expired

Digital-to-analog converter

US4404546A · kind A · utility

5Cited by
3References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 11, 1981
Grant dateSep 13, 1983
Priority date
Expiry dateDec 11, 2001

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03M1/82
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

An integrating digital-to-analog converter circuit includes an operational-amplifier based integrator, a plurality of constant current sources each providing constant current at a respective different level, and a plurality of switches each associated with a respective current source for coupling the same to the integrator. A plurality of digital counters are arranged to hold a predetermined portion of an n-bit digital word loaded therein and to count clock pulses until their contents reach a predetermined count. At those times, a carry pulse is generated in each such digital counter and the associated switch is opened to cut off the associated current source. Such a digital-to-analog converter circuit can convert data words of relatively high bit length without the need for an excessively high frequency clocking signal.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.