Temperature compensated crystal oscillator

Abstract

Abstract PURPOSE:To change the compensation for only some temperature by varying a level adjustment of a temperature section divided minutely depending on the number of stages of a voltage controlled filter independently. CONSTITUTION:A temperature detection section 30 generates a voltage with respect to temperature information in a range of temperature applying temperature compensation and a selection frequency of a voltage controlled filter VCF group is varied depending on the voltage. When the selection frequency at a temperature is decided, an output of the oscillation frequency of the oscillator 10 is obtained. This is adjusted to a required level by a level control group 40 and it is added by an adder 50. Then a series of voltage outputs is obtained with respect to the temperature information within the temperature compensation range. The AC temperature compensation information is given to a detector 60 to convert it into DC temperature information. The temperature compensation information is given to the voltage controlled crystal oscillator 70 to apply temperature compensation by a varactor diode, etc., in the oscillator 70. Thus, the compensation at some temperature only is to be varied.

Inventors

• 👤 Kotaro Yajima

Bibliographic Details