Active power supply filter
US5999039A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 1997 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Sep 26, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0995
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An active power supply filter effectively eliminates power supply noise using a resistive element and a capacitive element coupled at a node, and a switch with a control terminal controlled by the node. The active power supply filter is suitable for high frequency operation of a voltage-controlled oscillator (VCO) in a phase-locked loop (PLL) of a high-speed microprocessor. The active power supply filter removes VCO noise that would otherwise create jitter that reduces the effective clock cycle of the microprocessor. The active power supply filter is similarly useful in applications other than VCOs, PLLs, and microprocessors in which removal of substantial amounts of noise from the power supply is useful.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.