Patent ID: 9614555
Date: 2017-04-04
CPC Classifications: H01F,H04B,H04L,Y02D

Claim:
1. A transmission circuit configured to transmit a transmitting signal to a reception circuit through a transmitting AC coupling element, the reception circuit receiving a reception signal through a receiving AC coupling element, the transmitting AC coupling element being AC coupled to the receiving AC coupling element, the transmission circuit comprising: a drive signal generation circuit configured to generate a drive signal in synchronization with a transmission signal to be transmitted; and a drive circuit configured to cause, in response to the drive signal, a drive current to flow between both ends of the transmitting AC coupling element in synchronization with a rising edge and a falling edge of the transmission signal during a driving period set in advance, and apply an applied voltage to both of the ends of the transmitting AC coupling element after the driving period, wherein the drive circuit comprises: a first switching element comprising one end to which a first voltage is supplied and an other end connected to one end of the transmitting AC coupling element; a second switching element comprising one end to which a second voltage is supplied and an other end connected to the one end of the transmitting AC coupling element; a third switching element comprising one end to which the first voltage is supplied and an other end connected to an other end of the transmitting AC coupling element; a fourth switching element comprising one end to which the second voltage is supplied and an other end connected to the other end of the transmitting AC coupling element; a first impedance element connected between the one end and the other end of the first switching element; a second impedance element connected between the one end and the other end of the second switching element; a third impedance element connected between the one end and the other end of the third switching element; and a fourth impedance element connected between the one end and the other end of the fourth switching element, the drive signal generation circuit makes the first and fourth switching elements or the second and third switching elements conductive during the driving period and causes the drive current to flow, and the drive signal generation circuit makes, after the driving period, the first to fourth switching elements conductive and applies the applied voltage to both of the ends of the transmitting AC coupling element, and then makes the first to fourth switching elements non-conductive and applies a voltage between the first voltage and the second voltage, to both of the ends of the transmitting AC coupling element.