Voltage controlled oscillator suitable for complete implementation within a semiconductor integrated circuit
US5187450A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 1992 |
| Grant date | Feb 16, 1993 |
| Priority date | — |
| Expiry date | Mar 13, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03C3/40
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An embodiment of the present invention is a voltage controlled oscillator (VCO) comprised of a differential pair of transistors that have respective positive feedback paths with phase-lead networks cross-coupled. Each positive feedback path on each side has two different phase-lead branches. The two phase-lead branches have the same phase differences on each side of the differential pair, in order to maintain a symmetry that improves common-mode noise rejection on a voltage control differential input. Current-steering is used to control the mixture of currents that arrive at the bases of the differential transistor pair from the respective two different phase-lead branches, and thereby changing the frequency of the VCO.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.