| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric oscillator which can operate with low voltage, has high stability and oscillates with low power consumption and a low vibrator current. SOLUTION: In this Colpitts oscillator, a series circuit consisting of capacitors C1, C2 as a part of a load capacity is inserted and connected between a base of an oscillation transistor TR1 and the ground, the connection intermediate point A of this series circuit is connected via a resistor R2 to an emitter of the pnp-type transistor TR1, and an emitter resistor R1 is grounded. Also, a base of an npn-type transistor TR2 of an amplifier circuit is grounded via a capacitor C5, and is connected to the emitter of the transistor TR1. The base of the transistor TR1 is connected to a collector of the transistor TR2 which is grounded via a resistor R6 via a DC path circuit consisting of resistors R3, R4 and a path capacitor C4, a serial circuit consisting of a piezoelectric vibrator Xtal and a capacitor C3 is inserted and connected between the base of the transistor TR1 and the emitter of the transistor TR2, and the emitter of the transistor TR2 is connected to a power supply Vcc via a resistor R5. With this configuration, oscillation output is taken out from the collector of the transistor TR2 via a capacitor C6. COPYRIGHT: (C)2004,JPO&NCIPI
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