Low distortion crystal oscillator circuit
US5450042A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1994 |
| Grant date | Sep 12, 1995 |
| Priority date | — |
| Expiry date | Jun 8, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B5/364
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A crystal oscillator circuit that provides a low distortion clocking signal. The oscillator circuit incorporates an inverter circuit in combination with a diode connected transmission gate circuit. The transmission gate circuit includes two MOSFETs connected between input and output nodes of the inverter circuit. When the current at the input node goes high and the current at the output node goes low, one of the two transmission gate circuit MOSFETs will begin conducting such that current at the input node will be transferred to the output node, thus decreasing the voltage difference between the two nodes. Likewise, when the current at the output node goes high and the current at the input node goes low, the other MOSFET of the transmission gate circuit will begin to conduct such that current is transferred from the output node to the input node, again reducing the voltage difference between the input and output node. Additionally, the transmission gate circuit provides the impedance necessary to generate oscillation of the oscillator circuit at start-up to regulate the output voltage swing of the oscillator circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.