Fast CMOS charge pump circuit
US5363066A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 1993 |
| Grant date | Nov 8, 1994 |
| Priority date | — |
| Expiry date | Jun 16, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0896
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A charge pump circuit for a phase-locked loop circuit which provides substantially constant charge and discharge currents characterized by minimal overshoots and undershoots. The charge pump circuit includes a level shifter circuit which attenuates voltage swings in Up and Down signals from the phase detector and provides control signals. The charge pump circuit also includes a feedback circuit coupled to the level shifter which compares the output voltage of the charge pump to predetermined first and second reference voltages and increases and decreases the charge and discharge currents to minimize overshoot and undershoot noise as determined by the control signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.