System and method for a low voltage charge pump with large output voltage range
US6064251A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 27, 1997 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Aug 27, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/073
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A low voltage charge pump system with a large output voltage range is described. The charge pump system comprises eight charge pump stages, an output stage, and a four phase clock generator. The clock generator generates two sets of four phase shifted signals. The first set of four clock signals are coupled to the first four charge pump stages and have a logic high level of VCC. The second set of clock signals are coupled to the second four charge pump stages and have a logic high level of 2 VCC. Due to the body effect, the negative voltages at the charge pump output stages increases the threshold voltage of a pass transistor which couples the input and output in each charge pump. The larger high voltage level of the second set of clock signals enables the signals to overcome the body effect increased threshold voltages of the pass transistors. The pass transistors are then used to couple negative charge to the next charge pump stage, and positive charge to the preceding charge pump stage. The present invention charge pump system can thereby provide a large negative voltage output using a low power supply voltage. In the charge pump stages that receive the higher clock levels and i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.