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Patent Searching and Data


Title:
OSCILLATOR
Document Type and Number:
Japanese Patent JPH07115323
Kind Code:
A
Abstract:

PURPOSE: To decrease the number of capacitors that require large areas and to reduce the size of an oscillator by inserting a parallel circuit of a variable resistance circuit and a capacitor in series into a crystal vibrator and then changing the resistance value of the variable resistance circuit for control of the oscillation frequency.

CONSTITUTION: A parallel circuit of a capacitor Cp and a programmable variable resistance circuit is inserted in series into a crystal vibrator X as a compensating circuit. The programmable variable resistance circuit includes a circuit network where the resistances R-128R and the switches S1-S8 are connected togther in a ladder shape and a switch control circuit CPU. The switch control data are read out of a ROM based on the relevant temperature information detected by a temperature detecting circuit T.DET. Then the desired one of switches S1-S8 is closed via the circuit CPU. The circuit load capacity is varied to the vibrator X by the open/close combinations of those switches. Thus the oscillation frequency is controlled.


Inventors:
UCHIYAMA TOSHIICHI
MIYAYAMA TAKASHI
Application Number:
JP28044893A
Publication Date:
May 02, 1995
Filing Date:
October 14, 1993
Export Citation:
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Assignee:
TOYO COMMUNICATION EQUIP
International Classes:
H03B5/32; (IPC1-7): H03B5/32
Attorney, Agent or Firm:
鈴木 均