Patent ID: 8217726

Claim:
A semiconductor device capable of being selectively switched between an oscillation circuit and a signal input-output circuit, comprising: first and second external connecting terminals that are connectable to an oscillation device; an inverting amplifier, an input side of the inverting amplifier being electrically connected to the first external connecting terminal through a coupling capacitor, an output side of the inverting amplifier being electrically connected to the second external connecting terminal; a feedback resistor connected to the input side and the output side of the inverting amplifier; a bias stabilization circuit that stabilizes a bias applied to the coupling capacitor; a first signal input-output portion connected to the first external connecting terminal; and a second signal input-output portion connected to the second external connecting terminal, wherein when the semiconductor device is used as the oscillation circuit, the inverting amplifier and the bias stabilization circuit are brought into an operating state and the first and second signal input-output portions are brought into a non-operating state, and when the semiconductor device is used as the signal input-output circuit, the inverting amplifier and the bias stabilization circuit are brought into the non-operating state and the first and second signal input-output portions are brought into the operating state.