Voltage generation circuit and semiconductor device
A voltage generation circuit includes a voltage dividing circuit configured to divide an applied voltage; a bias circuit configured to generate a voltage by dividing a power source voltage supplied through a first input terminal; and a power source switching control circuit. The power source switching control circuit is configured to perform first processing of preventing a voltage supply from a power source line to the voltage dividing circuit, connecting the power source line to a first output terminal, and connecting a ground to a second output terminal, second processing of connecting the power source line and the ground to the voltage dividing circuit, and third processing of obtaining a voltage through the voltage dividing circuit by supplying a voltage generated by the bias circuit to the first output terminal and supplying the voltage generated by the bias circuit to the voltage dividing circuit.
1. A voltage generation circuit comprising:
a voltage dividing circuit configured to generate a first bias voltage of a first voltage value and a second bias voltage of a second voltage value by dividing an applied voltage, and output the first bias voltage to a first output terminal and the second bias voltage to a second output terminal;
a bias circuit configured to generate a voltage by dividing a power source voltage supplied through a first input terminal; and
a power source switching control circuit configured to:
perform, when a power source voltage corresponding to an element breakdown voltage is supplied to a power source line, first processing of stopping a voltage supply from the power source line to the voltage dividing circuit and connecting the power source line to the first output terminal and connecting a reference voltage point to the second output terminal,
perform, when a power source voltage that potentially exceeds the element breakdown voltage is supplied to the power source line, second processing of connecting the power source line and the reference voltage point to the voltage dividing circuit, and
perform, when the power source voltage is not supplied to the power source line but is supplied through the first input terminal, third processing of obtaining the second bias voltage through the voltage dividing circuit by supplying the voltage generated by the bias circuit to the first output terminal as the first bias voltage and supplying the voltage generated by the bias circuit to the voltage dividing circuit.
2. The voltage generation circuit according to claim 1 , wherein the power source switching control circuit executes the first to third processing in accordance with a result of a determination of each of:
whether the power source voltage that potentially exceeds the element breakdown voltage is input to the power source line,
whether the power source voltage that corresponds to the element breakdown voltage is input to the power source line, and
whether the power source voltage is input through the first input terminal.
3. A semiconductor device comprising:
the voltage generation circuit according to claim 1 ; and
an interface circuit that includes a processing circuit configured to communicate data with a host and in which the power source voltage is supplied from the voltage generation circuit to an element in the processing circuit.
4. The semiconductor device according to claim 3 , wherein the power source switching control circuit executes the first to third processing in accordance with a result of a determination of each of:
whether the power source voltage that potentially exceeds the element breakdown voltage is input to the power source line,
whether the power source voltage that corresponds to the element breakdown voltage is input to the power source line, and
whether the power source voltage is input through the first input terminal.