Converting a pulse-width modulation signal to an analog voltage
US6208280A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 1999 |
| Grant date | Mar 27, 2001 |
| Priority date | — |
| Expiry date | Jun 4, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/822
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for converting a pulse-width modulation (PWM) signal to an analog voltage signal. A current source is provided to supply electrical charge at a controllable rate to a ramp capacitor which, during successively occurring cycles of the PWM signal, alternatively receives electrical charge from the current source and discharges previously received electrical charge. A first sampling capacitor receives electrical charge from the ramp capacitor to output a feedback voltage to a feedback circuit to adjust the rate of electrical charge supplied by the current source, with the charge transferred to the first sampling capacitor determined in relation to the charge stored on the ramp capacitor over an entire PWM cycle. A second sampling capacitor receives electrical charge from the ramp capacitor to output the analog voltage, with the charge transferred to the second sampling capacitor determined in relation to the duty cycle of the PWM signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.