| 摘要 |
A voltage controlled crystal oscillator circuit, such as a Pierce oscillator circuit 200, has an amplifier 20 connected across a two-terminal (12,13) crystaloscillator element (11). Each terminal (12,13) of the oscillator element is connected through a separate varactor (31,41) to a common node (36) to which voltages (VA)are applied to pull (modify) the resonant oscillation frequency of the circuit. To improve linearity of resonant frequency shift vs. applied voltage, each terminal (12, 13) of the oscillator element 11 is connected through another separate varactor (30,40) to another common node 35 to which bias voltage (VB) is applied.
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