Semiconductor device and oscillation circuit
A semiconductor device including a first inverter circuit connected in parallel to a crystal vibrating element; a second inverter circuit connected to the first inverter circuit so as to share an input therewith, and outputting an oscillation signal; and a wave filter connected to the second inverter circuit and having a passband that is determined in advance and includes an oscillation frequency of the oscillation signal.
1. A semiconductor device, comprising:
a first inverter circuit connected in parallel to a crystal vibrating element;
a second inverter circuit connected to the first inverter circuit so as to share an input therewith, and output an oscillation signal; and
a wave filter connected to the second inverter circuit and having a passband that is determined in advance and includes an oscillation frequency of the oscillation signal,
wherein the wave filter is configured by a plurality of wave filters that are connected in series, and
the wave filter is a bandpass filter having a third inverter circuit, a capacitor connected in series to an input of the third inverter circuit, and a resistor connected between the input and an output of the third inverter circuit.
2. The semiconductor device of claim 1 , wherein a gate width ratio, which is a ratio of a gate width of a P-type field effect transistor to a gate width of an N-type field effect transistor, at the first inverter circuit and a gate width ratio of the second inverter circuit are substantially the same.
3. The semiconductor device of claim 1 , wherein at least one of a capacitance value of the capacitor or a resistance value of the resistor is variable.
4. The semiconductor device of claim 1 , wherein the second inverter circuit is disposed between a plurality of the first inverter circuits, as seen in a plan view.
5. An oscillation circuit, comprising:
the semiconductor device of claim 1 ; and
the crystal vibrating element connected in parallel to the first inverter circuit.