Semiconductor device having a complementary field effect transistor

A semiconductor device comprising:

• a buffer circuit that generates a power-supply voltage of a complementary field effect transistor circuit including a first field effect transistor of a first conductivity type and a second field effect transistor of a second conductivity type;
• a first replica transistor that is a replica of the first field effect transistor, the first replica transistor being diode-connected;
• a second replica transistor that is a replica of the second field effect transistor, the second replica transistor being diode-connected;
• a noninverting amplifier that includes first and second input terminals, a first output terminal, and a feedback resistor inserted between the first output terminal and the second input terminal;
• a comparator that includes third and fourth input terminals and a second output terminal;
• and
• a first input voltage generating circuit that generates a voltage that appears in the first output terminal when a total current value of currents flowing in the first and second replica transistors is equal to a predetermined first target value, the first input voltage generating circuit outputting the voltage to the third input terminal, wherein
• the first input terminal and the second output terminal are connected to each other, and the first output terminal and the fourth input terminal are connected to each other,
• the first and second replica transistors are inserted in a forward direction and in parallel between the second input terminal and a ground, and
• the buffer circuit generates the power-supply voltage, with a target voltage being a voltage that is output from the second output terminal.