Kabushiki Kaisha Toshiba

Taiwan Semiconductor Manufacturing Comp. Ltd.

Shunta Iguchi

Makoto Takamiya

Takayasu Sakurai

According to one embodiment, an oscillator circuit includes a resonant circuit and first and second negative-resistance circuits. Each of the first and second negative-resistance circuits includes a first power-supply terminal, a second power-supply terminal, an input terminal and an output terminal. The first and second negative-resistance circuits are connected in series between a first power supply and a second power supply at the first and second power-supply terminals, and connected parallel to the resonance circuit at the input and output terminals.

Oscillator circuit

A crystal oscillator circuit includes an oscillator configured to generate a signal having an oscillation amplitude. A high-pass filter is configured to filter the output signal to generate a filtered output signal. An automatic gain control (AGC) module is configured to generate an initial gain control signal when the filtered output signal is not received by the AGC module. The high-pass filter is configured to prevent the filtered output signal from being received by the AGC module when the oscillation amplitude is substantially equal to zero. The AGC module is configured to generate a steady-state gain control signal when the filtered output signal is received by the AGC module. A gain stage is configured to provide a first amount of gain to the oscillator module based on the initial gain control signal and a second amount of gain to the oscillator module based on the steady-state gain control signal.

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Tokyo, Japan

Shunta Iguchi