A transmission device of the present disclosure includes: a driver unit that transmits a data signal with use of a first voltage state, a second voltage state, and a third voltage state interposed between the first voltage state and the second voltage state, and is configured to make a voltage in the third voltage state changeable; and a controller that changes the voltage in the third voltage state to cause the driver unit to perform emphasis.

A ringing suppression circuit connected to a transmission line to suppress ringing caused by the transmission line transmitting a differential signal using a pair of signal lines, the differential signal varying between a high level and a low level, the pair of signal lines including a high potential signal line and a low potential signal line, the ringing suppression circuit including: an inter-line switching element that is connected between the pair of signal lines; a control portion that performs a ringing suppression operation in response to detecting a level change in the differential signal, wherein the ringing suppression operation turns on the inter-line switching element to decrease an impedance between the pair of signal lines; and a suppression operation prohibiting portion that prohibits the control portion from performing the ringing suppression operation in response to detecting a signal caused by a signal on the transmission line.

A ringing suppressor circuit is connected to a differential signal transmission line that includes a high potential signal line and low potential signal line pair for transmitting high and low level differential signals, and includes a ringing suppressor and a stopper. When the differential signal changes to a high level, the ringing suppressor suppresses ringing by lowering the impedance between the signal lines by turning ON of a switching element. When a differential signal voltage drops below a voltage lowering determination voltage, the stopper stops the impedance lowering function of the ringing suppressor by turning OFF another switching element.

A bidirectional data link includes a forward channel transmitter circuit and a forward channel receiver circuit. The forward channel transmitter circuit includes a forward channel driver circuit, and a back channel receiver circuit. The back channel receiver circuit is coupled to the forward channel driver circuit. The back channel receiver circuit includes a summation circuit and an active filter circuit. The summation circuit is coupled to the forward channel driver circuit. The active filter circuit is coupled to the summation circuit. The forward channel receiver circuit includes a forward channel receiver, and a back channel driver circuit. The back channel driver circuit is coupled to the forward channel receiver.

A digital receiver for decoding input data having three states includes a first input coupled to a first data line, a second input coupled to a second data line, a third input coupled to a third data line, and a fourth input coupled to a fourth data line. A first decoder is coupled to a first output, wherein the first decoder is for outputting first data signals in response to the sign of input data on the first data line minus input data on the second line. A second decoder is coupled to a second output, wherein the second decoder is for outputting second data signals in response to the sign of input data on the third data line minus input data on the fourth data line.

Described is an apparatus which comprises: a plurality of transmitter circuits on a first die; a plurality of receiver circuits on a second die; a plurality of data transmission lines communicatively coupling the first die to the second die for the plurality of transmitter circuits to transmit data bits in parallel to the plurality of receiver circuits; a termination circuit comprising a shared capacitor and a plurality of resistors, each corresponding to one of the plurality of conductive lines and each coupled to the shared capacitor; and a parallel coding block to code data transmitted by the plurality of transmitter circuits via the plurality of data transmission lines according to a direct current (DC) balanced code.

A PHY is coupled across split primary windings of an isolation transformer for differential data transmission and reception between PHYs and for DC isolation. Positive and negative low impedance terminals of a DC power supply are coupled to first and second secondary windings of the transformer as split center taps of the transformer. Respective ends of the wires in the wire pair are coupled to the other ends of the secondary windings. Therefore, the power supply conducts DC current through the secondary windings, while the differential data signals also flow through the secondary windings, generating corresponding differential data signals at the inputs to the PHY. The transformer also attenuates common mode noise. Therefore, the circuit makes multi-use of the isolation transformer, allowing fewer components to be used for the DC coupling, wire termination, and common mode noise cancellation.

A ringing suppression circuit connected to a transmission line to suppress ringing caused by the transmission line transmitting a differential signal using a pair of signal lines, the differential signal varying between a high level and a low level, the pair of signal lines including a high potential signal line and a low potential signal line, the ringing suppression circuit including: an inter-line switching element that is connected between the pair of signal lines; a control portion that performs a ringing suppression operation in response to detecting a level change in the differential signal, wherein the ringing suppression operation turns on the inter-line switching element to decrease an impedance between the pair of signal lines; and a suppression operation prohibiting portion that prohibits the control portion from performing the ringing suppression operation in response to detecting a signal caused by a signal on the transmission line.

A transmitting device of the present disclosure includes: a voltage generator that generates a predetermined voltage; a first driver including a first sub-driver and a second sub-driver, the first dub-driver that includes a first switch provided on a path from a first power source to a first output terminal, a second switch provided on a path from a second power source to the first output terminal, and a third switch provided on a path from the voltage generator to the first output terminal, and is allowed to set a voltage state of the first output terminal to any of a predetermined number of voltage states which are three or more voltage states, and the second sub-driver that is allowed to adjust a voltage in each of the voltage states of the first output terminal; and a controller that controls an operation of the first driver to perform emphasis.

A ringing suppression circuit applicable to a transmitter module in a controller area network is provided, which includes a CANH driver circuit, a CANL driver circuit, a first operable circuit transmitting a CAN high signal, a second operable circuit transmitting a CAN low signal, and a termination component connected between the first operable circuit and the second operable circuit. By sequentially turning on a first, second, and third transistor of the CANH driver circuit and sequentially turning on a fourth, fifth, and sixth transistor of the CANL driver circuit, conventional ringing phenomenon is effectively suppressed. A plurality of transistors may also be configured for implementing the CANH driver circuit or the CANL driver circuit for further reducing a glitch. The transmitter module employing the proposed ringing suppression circuit is able to pull the bus to a recessive state and meanwhile suppress the ringing and improve the maximum data rate.