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Crystal Oscillator

IP.com Disclosure Number: IPCOM000096166D
Original Publication Date: 1963-Jan-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Bryson, BL: AUTHOR

Abstract

Employment of two series connected crystals in an oscillator results in the minimization of any temperature effect upon the oscillator. The stability of the oscillator is increased and the control devices ordinarily required for obtaining stability in an oscillator are reduced.

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Crystal Oscillator

Employment of two series connected crystals in an oscillator results in the minimization of any temperature effect upon the oscillator. The stability of the oscillator is increased and the control devices ordinarily required for obtaining stability in an oscillator are reduced.

The two crystals selected have opposite temperature coefficients. In addition, they have slightly different characteristic frequencies. The associated circuitry employed with the crystals in the oscillator provides a constant phase shift. When these design considerations are met, the effect in the circuit is for one crystal to operate inductively with a temperature change and the other crystal to operate capacitively with a temperature change. If matching of the temperature coefficients takes place, the phase angles cancel and the resonant frequency of the oscillator remains substantially constant.

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