Digital amplifier
US7268621B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2005 |
| Grant date | Sep 11, 2007 |
| Priority date | — |
| Expiry date | Dec 27, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/351
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A threshold value adjustment circuit for adjusting a predetermined threshold value is provided in a stage followed by a protection circuit which starts protection operation when a load current flowing into an MOSFET exceeds the threshold value. A voltage proportional to a drain current and generated between the opposite ends of a current detection resistor Rd inserted between the high-side MOSFET and a positive power supply +V, and an output of an output voltage detection circuit for detecting the voltage amplitude of an analog signal from a low pass filter for modulating an output of a class D amplifier stage are inputted to the threshold value adjustment circuit. The threshold value adjustment circuit adjusts the threshold value in such a manner that a limit current of the MOSFET is set as the threshold value when the output voltage is large, and protection operation is started in response to a lower current than the limit current when the output voltage is small.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.