Charge pump drive signal recovery circuit
US6738273B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 9, 2002 |
| Grant date | May 18, 2004 |
| Priority date | — |
| Expiry date | Oct 9, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
At least upper order stages of a multi-stage charge pump contain respective drive signal recovery circuits, that enable the charge pump to operate over a larger voltage range and/or be driven by a very small input voltage. The switch control signal recovery circuit has an auxiliary NFET switch whose current flow path is series-coupled with a Schottky diode between the output voltage of the next lower order stage and a PFET switch drive line. The auxiliary switch controllably clamps the PFET switch drive line at a voltage that differs from the output voltage of the next lower order charge pump stage by the voltage drop across the Schottky diode. This effectively guarantees that the level-shifted line of that stage's transient clamp network will be biased to its appropriate operating voltage level, so that the clamp rail of this stage cannot hang up at a voltage level that is well below the output voltage from the next lower order stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.