Digitally temperature compensated voltage-controlled oscillator
US4746879A · kind A · utility
Inventors
Key dates
| Filing date | Aug 28, 1986 |
| Grant date | May 24, 1988 |
| Priority date | — |
| Expiry date | Aug 28, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L1/025
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digitally temperature compensated oscillator (TCO) system is provided which is capable of ascertaining and memorizing in an EEPROM-based look-up table, appropriate digital values of a temperature-compensating tuning voltage to the TCO during calibration. An on-board temperature sensing mechanism tracks variations in temperature in the TCO and produces an analog voltage value corresponding to the instantaneous temperature. The voltage value of the sensor output is digitized and designated to constitute an address into the EEPROM based look-up table. As the temperature changes, the digitized output of the temperature sensor and hence the address to the EEPROM changes accordingly. The TCO tuning voltage value corresponding to the address represented by the measured temperature is extracted from the values stored within the EEPROM table and then converted into a corresponding analog voltage which is used to drive the voltage-controlled oscillator (VCO) in order to maintain the output frequency of the TCO stabilized at a desired value. The EEPROM contained within the TCO is preferably calibrated during production, under the control of a calibration and test circuit which regulates the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.