Title:
DIGITAL TEMPERATURE COMPENSATED CRYSTAL OSCILLATOR
Document Type and Number:
Japanese Patent JP3198001
Kind Code:
B2
Abstract:
PURPOSE: To finely adjust the frequency without adversely affecting the reduction of the size of DTCXO.
CONSTITUTION: This crystal oscillator consists of a voltage output part 31a which senses the ambient temperature of a crystal vibrator and outputs a voltage corresponding to the temperature, an A/D converter 31b which converts the analog voltage from the voltage output part 31a into a digital value T, and a function part 31C which sets previously stored temperature compensation data in its internal V register by using the output value T as an address, and its output is supplied to an adder 41. This adder 41 adds the output, counted up or down by the number of pulses corresponding to the fine frequency adjustment quantity, to the output of the function part 31c and supplies its addition value to a D/A converter 11. Once a signal is inputted from an external input signal terminal 44, a signal transmission part 43 inhibits the data of the function part 31c from being set. An up pulse signal and a down pulse signal are supplied from external input signal terminals 45 and 46 to an up/down counter 42.
Inventors:
Takao Watanabe
Mutsuo Hayashi
Kazunari Matsumoto
Chikara Tsuchiya
Takashi Matsui
Mutsuo Hayashi
Kazunari Matsumoto
Chikara Tsuchiya
Takashi Matsui
Application Number:
JP30692593A
Publication Date:
August 13, 2001
Filing Date:
December 08, 1993
Export Citation:
Assignee:
株式会社明電舎
富士通株式会社
富士通株式会社
International Classes:
H03L1/02; H03B5/32; (IPC1-7): H03B5/32; H03L1/02
Domestic Patent References:
| JP3226103A | ||||
| JP63108806A | ||||
| JP61158723U | ||||
| JP5955791U | ||||
| JP56160041U |
Attorney, Agent or Firm:
Fujiya Shiga (1 person outside)