Method and apparatus for providing a high speed charge pump with low static error
US5663689A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1996 |
| Grant date | Sep 2, 1997 |
| Priority date | — |
| Expiry date | Jun 26, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0896
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A charge pump that receives complimentary metal-oxide semiconductor (CMOS) input signals, has high noise immunity, low static error and works at low power supply voltages. The charge pump includes a current switch for receiving a control signal from a control circuit and for generating a charge signal, a loop filter having a first and second node, and a common-mode loop for sensing the charge signal from the current switch and for providing a voltage level adjustment signal to the first node of the loop filter in response thereto. The common-mode loop includes a sensing circuit for sensing the voltage level at the first and second node, an averaging circuit for producing an averaged voltage signal, a comparing circuit for comparing the averaged voltage signal to a reference signal to produce a feedback control output signal, and a feedback current source for adjusting the voltage level at the first node of the loop in response to the feedback control output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.