| 摘要 |
PROBLEM TO BE SOLVED: To provide a crystal oscillation circuit capable of ensuring amplitude and duty factor of output signal in a sufficient level over a wide temperature range. SOLUTION: This crystal oscillation circuit 30 is provided with a frequency temperature compensating circuit 12, a crystal vibrator 14, transistors TR1, TR2, a negative resistor R5, an output load capacitor C5, and a constant current source 22 or the like. The crystal oscillation circuit 30 is oscillated by the frequency temperature compensating circuit 12, the crystal vibrator 14, the TR2, and capacitors C2, C3, C6 and its output terminal Out outputs a signal with a prescribed oscillation frequency, in response to the operation of the output TR1. A resistor R3 and the constant current source 22 have a positive temperature characteristic. Thus, a current I2 increases and a current I1 decreases accompanying a temperature rise. As a result, voltage at a node (e) is maintained, and the amplitude and the duty factor of the output signal can be ensured.
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