Circuit for driving a voltage controlled oscillator for frequency modulation
US7002416B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2004 |
| Grant date | Feb 21, 2006 |
| Priority date | — |
| Expiry date | Jul 31, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit provides an output signal for modulating the oscillation frequency of a voltage-controlled oscillator (VCO) in response to a control signal where the VCO includes a first voltage-controlled variable capacitance device for varying the oscillation frequency of the VCO according to the output signal. The circuit includes a charge pump providing a charge current to a first node, a first capacitor having a fixed capacitance and a second capacitor both coupled to the first node, and an amplifier providing the output signal. The second capacitor includes a second voltage-controlled variable capacitance device having the same device structure as the first voltage-controlled variable capacitance device of the VCO. In operation, a voltage change at the first node is generated in response to the charge current and the output signal causes the same voltage change to be applied across the first voltage-controlled variable capacitance device of the VCO.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.