Oscillator calibration method and circuit and radio with oscillator
US6020790A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1998 |
| Grant date | Feb 1, 2000 |
| Priority date | — |
| Expiry date | Jul 30, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J2200/07
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a method of calibration of a voltage controlled oscillator (VCO), the VCO (100) provides an output signal which is used to drive a dividing oscillator (10) such as a relaxation oscillator (RO). The RO has at least two states, one in which the RO provides an output signal which has a first frequency that is related to the VCO output signal by a first ratio (e.g. 1/N) and one in which the relaxation oscillator provides a RO output signal which has a second frequency that is related to the VCO output signal by a second ratio (e.g. 1/(N+1)). By measuring the first and second frequencies (and knowing the relationship between the first and second ratios), the VCO frequency is calculated and stored (110). Several VCO frequencies can be calculated and stored for several applied voltages. As a result the VCO can be driven to any selected frequency in the calibrated range and can be used to provide an injection frequency for a radio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.