| 摘要 |
An oscillator circuit (30, 40) for starting-up and operating at low voltages has been provided. The oscillator circuit includes an inverter circuit (31, 41) coupled across first and second terminals of a resonant circuit (14). The inverter circuit includes a push-pull driver stage having a P-channel transistor (18) and an N-channel transistor (20). The common drain electrodes of each are coupled to the second terminal of the resonant circuit. The source electrodes of the P- and N-channel transistors are respectively coupled to first and second supply voltage terminals. The gate electrode of the first transistor is coupled to the first terminal of resonant circuit. The inverter circuit further includes a circuit (32, 42) for shifting the voltage level applied to the gate electrode of the second transistor, relative to the voltage applied to the gate electrode of the first transistor, by a predetermined voltage. This has the effect of reducing the required operating voltage range of the inverter circuit while still maintaining both transistors active.
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