A transmission device of the disclosure includes: a generator unit that generates, on the basis of a control signal, a transmission symbol signal that indicates a sequence of transmission symbols; an output control unit that generates an output control signal on the basis of the transmission symbol signal; and a driver unit that generates, on the basis of the output control signal, a first output signal, a second output signal, and a third output signal. The generator unit generates the transmission symbol signal on the basis of the control signal, to allow the first output signal, the second output signal, and the third output signal to exchange signal patterns with one another.

A transmission device of the disclosure includes: a generator unit that generates, on the basis of a control signal, a transmission symbol signal that indicates a sequence of transmission symbols; an output control unit that generates an output control signal on the basis of the transmission symbol signal; and a driver unit that generates, on the basis of the output control signal, a first output signal, a second output signal, and a third output signal. The generator unit generates the transmission symbol signal on the basis of the control signal, to allow the first output signal, the second output signal, and the third output signal to exchange signal patterns with one another.

A communication apparatus includes a first substrate including a first transmission line, a metal portion functioning as a ground for the first substrate, spaced apart from the first transmission line, and a first termination circuit configured to terminate the first transmission line. The first substrate is fixed to any one of surfaces of the metal portion other than a surface where the first transmission line is disposed.

Apparatus might include a first plurality of signal lines, a second plurality of signal lines, a controller, a first die, and a second die. The controller, the first die, and the second die might each be connected to the first plurality of signal lines and connected to the second plurality of signal lines. The first die and the second die might each include termination circuitry connected to a particular signal line of the second plurality of signal lines. The first die might be configured to activate its termination circuitry in response to receiving a particular combination of signal values on the first plurality of signal lines. The second die might be configured to deactivate its termination circuitry in response to receiving the particular combination of signal values on the first plurality of signal lines.

Memory devices might include an input/output (I/O) node, a termination device, an array of memory cells in communication with the I/O node through the termination device, and control circuitry, wherein the control circuitry is configured to compare an address received by the memory device to a plurality of instances of address information stored in the memory device. Each instance of address information of the plurality of instances of address information might correspond to a respective termination value stored in the memory device. In response to the memory device receiving an address matching an instance of address information stored in the memory device, the control circuitry might further be configured to activate the termination device using the respective termination value corresponding to the instance of address information matching the received address.

A communication system according to an embodiment of the present disclosure is a communication system that transmits data from a plurality of transmission devices to one reception device via a pair of signal lines. In the communication system, each of the transmission devices includes: a mode controller that controls a transmission mode; a transmission data generator that generates the data in accordance with the transmission mode; and a data transmitter that transmits the generated data to the reception device. In a case where the transmission mode of a first transmission device is an HS mode, the mode controller of a second transmission device turns the transmission mode of the second transmission device to a termination mode in which an output terminal of the second transmission device is terminated.

A PoDL system that uses a center-tapped transformer, for galvanic isolation of the PHY, has AC-coupling capacitors in series between the transmission wires and the transformer's secondary windings for blocking DC voltages generated by a PSE power supply. The center tap is conventionally connected to ground. As a result, one capacitor sees the full VPSE voltage across it, and the other capacitor sees approximately 0 V across it. Since the effective value of a ceramic capacitor significantly reduces with increasing DC bias voltages across it, the effective values of the capacitors will be very different, resulting in unbalanced data paths. This can lead to conversion of common mode noise and corrupt the data. To avoid this, a resistor divider is used to generate VPSE/2, and this voltage is applied to the center tap of the transformer. Therefore, the DC voltage across each capacitor is approximately VPSE/2, so their values remain equal.

A termination circuit, including a termination resistor, a first switch circuit, a second switch circuit, and a control circuit, is provided. A first end of the termination resistor is coupled to a signal pad. A first end of the first switch circuit is coupled to a second end of the termination resistor. A first end of the second switch circuit is coupled to a second end of the first switch circuit. A second end of the second switch circuit is coupled to a reference voltage line. During a period when the second switch circuit is turned on, the control circuit turns on the first switch circuit with a bias voltage. During a period when the second switch circuit is turned off, the control circuit turns off the first switch circuit with a voltage of the first end of the first switch circuit.

A termination circuit, including a termination resistor, a first switch circuit, a second switch circuit, and a control circuit, is provided. A first end of the termination resistor is coupled to a signal pad. A first end of the first switch circuit is coupled to a second end of the termination resistor. A first end of the second switch circuit is coupled to a second end of the first switch circuit. A second end of the second switch circuit is coupled to a reference voltage line. During a period when the second switch circuit is turned on, the control circuit turns on the first switch circuit with a bias voltage. During a period when the second switch circuit is turned off, the control circuit turns off the first switch circuit with a voltage of the first end of the first switch circuit.

A control device includes a casing and a control circuit substrate arranged inside the casing. The control circuit substrate includes: a control circuit mounted on the control circuit substrate; an internal connector connectable to a communication cable inside the casing, the communication cable being connected to an expansion circuit substrate; and an external connector connectable to another communication cable outside the casing, the another communication cable being connected to another expansion circuit substrate. The control circuit is connected to the internal connector and the external connector in parallel.