PIECE-CRYSTAL OSCILLATOR AND OSCILLATION DEVICE

摘要

A crystal oscillator includes: an oscillation circuit; first and second oscillation circuits connected to first and second temperature detection crystal units, respectively; a heating portion configured to constantly maintain an ambient temperature; a frequency difference detection portion that obtains, as a temperature detection value, “{(f2−f1)/f1}−{(f2r−f1r)/f1r}”, where “f1” and “f2” denote oscillation frequencies of the first and second oscillation circuits, respectively, and “f1r” and “f2r” denote oscillation frequencies of the first and second oscillation circuits, respectively, at a reference temperature; an accumulator that accumulates the temperature detection value; a rounding processing portion that performs rounding for the temperature detection value accumulated in the accumulator depending on a rounding factor designated independently from the accumulation number; and a heating control portion that controls power supplied to the heating portion based on the temperature detection value subjected to the rounding in the rounding processing portion.

主权项

1. A crystal oscillator, comprising:
an oscillation circuit, being connected to a crystal unit for generating an oscillator output; first and second oscillation circuits, being connected to first and second temperature detection crystal units, respectively; a heating portion for constantly maintaining an ambient temperature of each of the crystal units; a frequency difference detection portion that obtains, as a temperature detection value, a digital value corresponding to a difference value between a value corresponding to a difference between frequencies f1 and f1r and a value corresponding to a difference between frequencies f2 and f2r, where “f1” denotes an oscillation frequency of the first oscillation circuit, “f1r” denotes an oscillation frequency of the first oscillation circuit at a reference temperature, “f2” denotes an oscillation frequency of the second oscillation circuit, and “f2r” denotes an oscillation frequency of the second oscillation circuit at the reference temperature; an accumulator that accumulates the temperature detection value as the digital value obtained from the frequency difference detection portion depending on a designated accumulation number; a rounding processing portion that performs rounding for the temperature detection value accumulated in the accumulator depending on a rounding factor designated independently from designation of the accumulation number; and a heating control portion that controls power supplied to a heating portion based on the temperature detection value subjected to the rounding in the rounding processing portion.