Circuit to spread the spectrum of a PWM signal
US8115523B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 12, 2008 |
| Grant date | Feb 14, 2012 |
| Priority date | — |
| Expiry date | Jun 3, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J7/345
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus is provided. The apparatus comprises a first current source and a second current source that charge and discharge a capacitor. Coupled between the capacitor and the second current source is a switch that can be actuated and deactuated by a controller. Preferably, the controller is coupled to the capacitor and receives a first threshold voltage and a second threshold voltage so that it can actuate the switch if the voltage across the capacitor is greater than the first threshold voltage and deactuate the switch if the voltage across the capacitor is less than the second threshold voltage. Additionally, there is a comparator that is coupled to the capacitor that compares the voltage across the capacitor to a reference voltage, and there is a a multiplexer that is coupled to the capacitor and that is coupled to the comparator. The multiplexer outputs the voltage across the capacitor if the voltage across the capacitor is greater than the reference voltage and outputs the reference voltage if the voltage across the capacitor is less than the reference voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.