Triangular-wave generating circuit synchronized with an external circuit
US8294494B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 2007 |
| Grant date | Oct 23, 2012 |
| Priority date | — |
| Expiry date | Feb 8, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K4/502
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A charge-discharge circuit charges or discharges a capacitor having a fixed electric potential at one end. A first comparator compares an output voltage of the capacitor with a first threshold voltage and outputs a first comparison signal in accordance with a comparison result. An edge detecting circuit detects an edge of a synchronization signal input from the outside and having a frequency of about ½ of a triangular-wave signal generated by the triangular-wave generating circuit, and outputs an edge detection signal that will be at a predetermined level for each of the detected edges. A charge-discharge controller receives the first comparison signal that is output from the first comparator and the edge detection signal that is output from the edge detecting circuit, and switches between a charge state and a discharge state of the charge-discharge circuit in accordance with a level transition of these signals. A voltage of the capacitor is output as a triangular-wave signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.