Abstract: A semiconductor device that outputs a high-speed and large-current pulse is provided. The semiconductor device includes: a first N channel transistor having its gate receiving a second voltage as its input; a first resistance element having its second terminal connected to a drain of the first N channel transistor; a second resistance element having its first terminal connected to a source of the first N channel transistor; a second N channel transistor having its gate receiving a second voltage as its input; a third resistance element having its second terminal connected to a drain of the second N channel transistor; a fourth resistance element having its first terminal connected to a source of the second N channel transistor; and an isolator having its first terminal connected to the drain of the first N channel transistor and having its second terminal connected to the drain of the second N channel transistor.

Abstract: A disconnection detector circuit that can favorably inspect a connection state of a wire without increase in parasitic capacitance is provided. A semiconductor device includes, in one package, a first integrated circuit including a transformer including a primary coil and a secondary coil, and a second integrated circuit connected to a midpoint and one end of the secondary coil. The second integrated circuit includes a reference line and a detector circuit. The reference line connects the midpoint of the secondary coil and a reference potential. On basis of a potential at a predetermined reference point of the first power supply line, the detector circuit detects whether a connection state between the second integrated circuit and the secondary coil is normal or abnormal.

Abstract: A DC-DC converter includes a high-side switch coupled between a first power supply and an output terminal, a low-side switch coupled between a second power supply and the output terminal, an inductor coupled to the output terminal, and a reverse current monitoring circuit that determines that a reverse current from the inductor to the output terminal occurs when the output terminal becomes a high voltage during a state in which the high-side switch and the low-side switch are in a dead time.

Abstract: A DC-DC converter includes a high-side switch coupled between a first power supply and an output terminal, a low-side switch coupled between a second power supply and the output terminal, an inductor coupled to the output terminal, and a reverse current monitoring circuit that determines that a reverse current from the inductor to the output terminal occurs when the output terminal becomes a high voltage during a state in which the high-side switch and the low-side switch are in a dead time.