| 摘要 |
PROBLEM TO BE SOLVED: To provide a crystal oscillation circuit that outputs an oscillation output without causing a delay in a start time even at a low voltage operation. SOLUTION: The crystal oscillation circuit is provided with an oscillation circuit 2 including; a crystal vibrator 24; 1st and 2nd transistors(TRs) 30, 29 whose drains are connected in common; 1st, 2nd, 3rd, 4th resistors 34, 33, 32, 31 of series connection for applying a voltage to gates of the 1st and 2nd TRs 30, 29; a 5th resistor 35 in feedback connection between a midpoint of the 2nd and 3rd resistors 33, 32 and drains of the 1st and 2nd TRs 30, 29; a 1st capacitor 27; a 1st and 2nd variable capacitor 25, 26 25; a 2nd capacitor 28; and a load capacitor of the crystal vibrator selected from the 2nd variable capacitor 26, an amplifier 4 that receives an oscillation output from the oscillation circuit 2 and amplifies the output, and a constant voltage circuit 1 that provides a constant voltage to the oscillation circuit 2 and the amplifier 4.
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