Frequency synthesizer with VCO output control
US5335365A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 7, 1993 |
| Grant date | Aug 2, 1994 |
| Priority date | — |
| Expiry date | Sep 7, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A frequency synthesizer circuit, having first and second modes of operation, comprises a voltage-controlled oscillator (VCO) (64), a low-pass filter (74), a phase-locked loop (PLL) (67), an analog-to-digital converter (50), a digital-to-analog converter (56), a controller (48), and a VCO input switch. During the first mode, the VCO input switch couples the control input of the VCO to a control signal produced by the PLL, and the analog-to-digital converter measures the control signal and provides it to the controller which stores the control voltage measured by the analog-to-digital converter. During the second mode, the VCO input switch couples the control input of the VCO to the digital-to-analog converter which applies the stored control to the control input of the VCO.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.