Abstract: A semiconductor circuit apparatus of the present disclosure includes a control circuit controlling a clock signal externally input, a drive circuit performing a switching operation according to a pulse signal provided by the control circuit, a series connection circuit including an inductor element, a switch element, and a capacitive element connected in series between a signal line and a fixed potential node, the series connection circuit forming an LC resonance circuit, and a level detection circuit having an input end connected to the signal line. An output from the level detection circuit is fed back to the control circuit.

Abstract: A semiconductor circuit apparatus of the present disclosure includes a control circuit controlling a clock signal externally input, a drive circuit performing a switching operation according to a pulse signal provided by the control circuit, a series connection circuit including an inductor element, a switch element, and a capacitive element connected in series between a signal line and a fixed potential node, the series connection circuit forming an LC resonance circuit, and a level detection circuit having an input end connected to the signal line. An output from the level detection circuit is fed back to the control circuit.

Abstract: The present invention relates to a variable gain circuit including: a first transistor and a second transistor each having a control electrode connected to a circuit input terminal; a load connected between a first power supply and a first electrode of at least one of the first transistor and the second transistor; a third transistor and a fourth transistor having second electrodes connected to the first transistor and the second transistor, respectively, and each having a first electrode and a control electrode connected to each other; a first variable current source connected between a second power supply and the second electrodes of the first transistor and the third transistor and having a current value variable according to an external control signal; a second variable current source connected between the second power supply and the second electrodes of the second transistor and the fourth transistor and having a current value variable according to the control signal; a current source connected between t

Abstract: The present invention relates to a variable gain circuit including: a first transistor and a second transistor each having a control electrode connected to a circuit input terminal; a load connected between a first power supply and a first electrode of at least one of the first transistor and the second transistor; a third transistor and a fourth transistor having second electrodes connected to the first transistor and the second transistor, respectively, and each having a first electrode and a control electrode connected to each other; a first variable current source connected between a second power supply and the second electrodes of the first transistor and the third transistor, and having a current value variable according to an external control signal; a second variable current source connected between the second power supply and the second electrodes of the second transistor and the fourth transistor, and having a current value variable according to the control signal; a current source connected between