A high-frequency high-linear input buffer includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a signal panning unit. A gate terminal of the first MOS transistor is used as an input terminal of the buffer. A current input terminal of the first MOS transistor is connected to a current output terminal of the second MOS transistor. A current output terminal of the first MOS transistor is connected to a current input terminal of the third MOS transistor. A current input terminal of the second MOS transistor is connected to a gate terminal of the third MOS transistor. An input terminal of the signal panning unit is connected to an input terminal of the buffer. An output terminal of the signal panning unit is connected to a gate terminal of the second MOS transistor. An output terminal of the third MOS transistor is connected to ground.

An example driver circuit includes a termination voltage circuit and a termination element coupled to the termination voltage circuit. The driver circuit also includes a current source switch coupled the termination element via a node. The driver circuit further includes a current source coupled to the current source switch. The current source switch and the termination voltage circuit are controlled via a control signal. The termination voltage circuit is to generate a termination voltage to match a node voltage of the node based on the control signal. The driver circuit further includes a load coupled to the termination element and the current source switch via the node. The driver circuit further includes a load voltage source coupled to the load. The node voltage is generated based on the load and the load voltage source.

A reference buffer circuit for an analog-to-digital converter is provided. The reference buffer circuit includes a first input node configured to receive a first bias signal of a first polarity from a first signal line. Further, the reference buffer circuit includes a second input node configured to receive a second bias signal of a second polarity from a second signal line. Additionally, the reference buffer circuit includes a first output node configured to output a first reference signal of the first polarity. A first buffer amplifier is coupled between the first input node and the first output node. The reference buffer circuit includes in addition a second output node configured to output a second reference signal of the second polarity. A second buffer amplifier is coupled between the second input node and the second output node. Further, the reference buffer circuit includes a first coupling path comprising a first capacitive element. The first coupling path is coupled between the first output node and the second input node. In addition, the reference buffer circuit includes a second coupling path comprising a second capacitive element. The second coupling path is coupled between the second output node and the first input node.

A high-frequency high-linear input buffer includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a signal panning unit. A gate terminal of the first MOS transistor is used as an input terminal of the buffer. A current input terminal of the first MOS transistor is connected to a current output terminal of the second MOS transistor. A current output terminal of the first MOS transistor is connected to a current input terminal of the third MOS transistor. A current input terminal of the second MOS transistor is connected to a gate terminal of the third MOS transistor. An input terminal of the signal panning unit is connected to an input terminal of the buffer. An output terminal of the signal panning unit is connected to a gate terminal of the second MOS transistor. An output terminal of the third MOS transistor is connected to ground.

Provided is a control circuit that controls the amplitude by using a voltage regulator and that has improved accuracy in amplitude control.

The control circuit includes a first voltage regulator and a second voltage regulator. The first voltage regulator in the control circuit generates one of a pair of voltages from a predetermined reference voltage and supplies the one of the pair of voltages to one of a power supply terminal and a ground terminal of a driver. In addition, the second voltage regulator generates the other of the pair of voltages from the one of the pair of voltages and supplies the other of the pair of voltages to the other of the power supply terminal and the ground terminal.

A semiconductor apparatus includes a calibration circuit and a main driver. The calibration circuit is configured to generate a first calibration code when set to have a positive offset and generate a second calibration code when set to have a negative offset complementary to the positive offset. The main driver is configured to set a resistance value of the main driver based on the first and second calibration codes.

A semiconductor apparatus includes a calibration circuit and a main driver. The calibration circuit is configured to generate a first calibration code when set to have a positive offset and generate a second calibration code when set to have a negative offset complementary to the positive offset. The main driver is configured to set a resistance value of the main driver based on the first and second calibration codes.

An example apparatus includes a line driver and an interface circuit. The line driver has a plurality of source-series terminated (SST) driver segments including switching circuitry to selectively switch among at least three voltage-reference levels to drive an output node, common to each of the SST driver segments, in response to received digital signals by switching at a rate that is faster than a baud rate characterizing the received digital signals. The interface circuit drives a transmission link, in response to a drive signal at the output node, with an analog signal representing an oversampling of the received digital signals.

An example apparatus includes a line driver and an interface circuit. The line driver has a plurality of source-series terminated (SST) driver segments including switching circuitry to selectively switch among at least three voltage-reference levels to drive an output node, common to each of the SST driver segments, in response to received digital signals by switching at a rate that is faster than a baud rate characterizing the received digital signals. The interface circuit drives a transmission link, in response to a drive signal at the output node, with an analog signal representing an oversampling of the received digital signals.

A circuit device includes first and second output signal lines from which first and second output signals constituting differential output signals are output, and first to n-th output drivers coupled to the first and second output signal lines. In a first mode, i number of output drivers of the first to n-th output drivers drive the first and second output signal lines based on first and second input signals constituting differential input signals. In a second mode, j number of output drivers of the first to n-th output drivers drive the first and second output signal lines based on the first and second input signals.