External oscillator resistor detection circuit
US6624710B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 2001 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | Jan 4, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K3/03
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An integrated circuit chip includes an RC oscillator circuit. The frequency of the output signal generated by the oscillator output signal is set as a function of a value of an included internal resistor integrated on the chip. An external resistor may be connected to the chip to allow a user to manipulate the oscillator output signal frequency. A detection circuit on the chip detects the presence of the connected external resistor. Responsive to that detection, a substitution circuit operates to substitute the connected external resistor for the internal resistor in the RC oscillator circuit. This effectuates a change of the frequency of the oscillator output signal to instead be set as a function of a value of that connected external resistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.