Patent · US Expired

Clock-controlled pulse width modulator

US4827261A · kind A · utility

5Cited by
8References
8Claims
0Family size

Inventors

Key dates

Filing dateNov 4, 1987
Grant dateMay 2, 1989
Priority date
Expiry dateNov 4, 2007

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03M7/08
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A clock-controlled pulse width modulator comprising an integrator for receiving a variable input voltage and producing an output having a triangular waveform, the integrator including a capacitor which is charged at a rate proportioal to the input voltage and discharged at a rate proportional to the difference between a reference voltage and the input voltage, the charging and discharging occurring during a time interval T.sub.o, a clock pulse source for generating a continuous series of clock pulses, a counter receiving the clock pulses and producing a binary control signal which changes state in response to the counting of a preselected number of clock pulses, the control signal having a period T.sub.o, and control means for terminating the charging of the capacitor and initiating the discharging of the capacitor in response to the first clock pulse following a selected transition in the control signal, and means for terminating the discharging of the capacitor and initiating the charging of the capacitor in response to the first clock pulse following the discharge of the capacitor to a preselected threshold level.

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