Reconfigurable counter and pulse width modulator (PWM) using same
US5485487A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 1994 |
| Grant date | Jan 16, 1996 |
| Priority date | — |
| Expiry date | Feb 25, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K23/665
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A pulse width modulator (20) includes a reconfigurable counter (30) whose width is determined by mode control bits. In one embodiment, a decoder (24) decodes the mode control bits to provide decoded width control signals to the reconfigurable counter (30). The width control signals enable selected least significant counter cells (101-107) of the reconfigurable counter (30) in a binary-to-thermometer fashion. Thus, unused counter cells are disabled, reducing power. The pulse width modulator (20) also includes an output circuit (25) which provides a pulse width modulated output signal having a duty cycle determined by a proportion of a cycle of the reconfigurable counter (30) during which a comparator (23) detects that an output of the reconfigurable counter (30) has reached a value of an input number. A portion of the comparator (23) may also be disabled in response to the width control signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.