Method for sensing the output voltage of a charge pump circuit without applying a load to the output stage
US6344959B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 30, 1999 |
| Grant date | Feb 5, 2002 |
| Priority date | — |
| Expiry date | Apr 30, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/073
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The presently disclosed method and apparatus provides the sensing of an output voltage of a charge pump without applying a load to the output stage. In the charge pump the voltage change which occurs across a capacitor of a stage of the charge pump when the charge pump transfers charge to the next stage is proportional to the difference between the voltage at the output of the charge pump under load, and the voltage which will be developed at the output of the charge pump with no load. There is an interval in the timing of the charge pump cycle after the first stage capacitor has transferred its charge to a second stage capacitor where the high side of the first capacitor has not yet been connected to the line voltage. During this interval the charge pump undervoltage detection circuit measures the voltage at the high side of the capacitor and compares this measured voltage to a reference voltage. When the voltage at the high side of the capacitor is below the reference voltage, it can be accurately inferred that the voltage at the output of the charge pump is more than a certain voltage below what the output voltage would be if it was unloaded. The amount that the output voltage i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.