Abstract: An isolation amplifier of an embodiment includes: a primary circuit including an encoder configured to encode an input signal and output the encoded input signal and an anomaly detection circuit configured to detect anomaly having occurred to the input signal and generate a detection signal; an isolation unit configured to insulate the primary circuit from a secondary circuit; an output circuit configured to generate an output signal corresponding to the input signal; and an anomaly-input sensing-output circuit configured to generate an output signal from the secondary circuit by changing the output signal from the output circuit based on the detection signal.

Abstract: A signal transmission device according to the embodiment includes: a first integrated circuit chip provided with a first coil that constitutes the isolation transformer; a printed circuit board provided with a second coil that is magnetically coupled with the first coil to form the insulating transformer; a second integrated circuit chip having a first connection terminal and a second connection terminal provided on the upper surface; a first wire that electrically connects between one end of the second coil and the first connection terminal; and a second wire that electrically connects between the other end of the second coil and the second connection terminal, wherein the second coil is provided only in the wiring layer of the printed circuit board, which has a single wiring layer structure.

Abstract: A semiconductor device includes: a first semiconductor chip including a first coil that generates a magnetic field signal; a wiring board including a second coil, a third coil, and a twisted pair wiring, the second coil being disposed to face the first coil and receiving the magnetic field signal generated by the first coil, the twisted pair wiring connecting the second coil with the third coil; and a second semiconductor chip including a fourth coil disposed to face the third coil and receiving a magnetic field signal generated by the third coil.

Abstract: An isolation amplifier of an embodiment includes: a primary circuit including an encoder configured to encode an input signal and output the encoded input signal and an anomaly detection circuit configured to detect anomaly having occurred to the input signal and generate a detection signal; an isolation unit configured to insulate the primary circuit from a secondary circuit; an output circuit configured to generate an output signal corresponding to the input signal; and an anomaly-input sensing-output circuit configured to generate an output signal from the secondary circuit by changing the output signal from the output circuit based on the detection signal.

Abstract: According to one embodiment, an RSSI signal error-detection protection circuit configured with respect to an RSSI circuit outputting an RSSI signal on a basis of an output level of an amplifier amplifying intermediate frequency signal outputted from a mixer circuit includes an RSSI operation control unit configured to switch between operation and non-operation of the RSSI circuit by controlling the lock detection signal outputted from the PLL circuit configured to control a local oscillation frequency signal inputted from the mixer circuit.