Precision clock synthesizer using RC oscillator and calibration circuit
US6404246B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2000 |
| Grant date | Jun 11, 2002 |
| Priority date | — |
| Expiry date | Dec 20, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/087
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A system and method of generating an output signal of very precise frequency without the use of a crystal oscillator. An input signal is generated using any convenient such as an RC oscillator. A circuit for producing a frequency-controlled output signal comprises a phase lock loop having a VCO and a down counter. The down counter reduces the frequency of a VCO clock signal in accordance with a down count value. The down count value is loaded in a register and stored in non-volatile memory. The down count value is set during a calibration operation using a precision external clock signal. In this way, a clock signal with a highly precise frequency is generated without using a crystal oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.