Current starved inverter voltage controlled oscillator
US5349311A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 23, 1992 |
| Grant date | Sep 20, 1994 |
| Priority date | — |
| Expiry date | Nov 23, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A voltage controlled oscillator (VCO) operating as a variable length, variable delay, ring oscillator having a current starved inverter and an anti high-gain circuit for each stage. A VCO feedback signal is compared with a reference frequency obtained, for example, from a system crystal oscillator. A phase and frequency detector monitors these two input signals and issues "up" or "down" commands to a digital counter. This digital counter delivers select signals via a decoder and also drives a Digital to Analog Converter ("DAC"). The digital select signal from the counter chooses an operational stage from the multi-stage, tandem-connected VCO. A broadband operation for the VCO is achieved by overlapping the individual frequency ranges associated with each of the individual stages. The DAC moves the operation along each selected frequency range associated with a selected stage until a system lock between the VCO output and the crystal references is achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.