Circuit and method for switching PFM and PWM
US7446621B2 · kind B2 · utility
4Cited by
1References
11Claims
0Family size
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Key dates
| Filing date | Jun 6, 2007 |
| Grant date | Nov 4, 2008 |
| Priority date | — |
| Expiry date | Jun 22, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K7/10
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The switching method between pulse frequency modulation and pulse width modulation signals is first based on an output voltage of a power transistor to generate a corresponding pulse frequency modulation signal. Next, it is determined whether the corresponding pulse frequency modulation signal has reached its maximal frequency. If so, the initial pulse width modulation signal is adjusted to have the same width as the pulse frequency modulation signal. Thereafter, the adjusted pulse width modulation signal is outputted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.