Voltage controlled oscillator including voltage controlled delay circuit with power supply noise isolation
US5559476A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1995 |
| Grant date | Sep 24, 1996 |
| Priority date | — |
| Expiry date | May 31, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0995
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A VCO includes a ring oscillator formed by connecting a plurality of voltage controlled inverting delay cells together, and a plurality of transistors for providing control voltages to the plurality of voltage controlled inverting delay cells. Preferably, each transistor has a drain connected to a reference voltage, and a source connected to a voltage controlled inverting delay cell paired to that transistor. Consequently, each transistor acts as a source-follower so that it provides a control voltage to its corresponding voltage controlled inverting delay cell which follows a control voltage driving its gate, thereby isolating the control voltage provided to its corresponding voltage controlled inverting delay cell from power supply noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.