Method and apparatus for calibrating a ramp signal
US7573250B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 19, 2005 |
| Grant date | Aug 11, 2009 |
| Priority date | — |
| Expiry date | Jul 26, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0025
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit for calibrating an oscillating ramp signal to a variable DC reference signal in accordance with an embodiment of the present application includes a circuit for setting a predetermined time period during which a charging capacitor can charge and thus determining a ramp oscillator frequency; a variable current source for providing a charging current to the charging capacitor; a circuit for selecting the charging current fed by the variable current source to said charging capacitor; and a circuit for comparing the oscillating ramp signal to the variable DC reference signal and for supplying a signal to the selecting circuit for controlling the amount of current supplied to said charging capacitor thereby determining the charging voltage across said capacitor at the end of said predetermined time period.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.