A digital differential line receiver includes a differential signal to single-ended conversion amplifier coupled to receive a data line and data-complement line of a differential signal; a first termination resistor coupled to the data line of the differential signal; a second termination resistor coupled to the data-complement line of the differential signal; a first impedance-adjusting transistor coupled between the first termination resistor and a common mode line; a second impedance-adjusting transistor coupled between the second termination resistor and the common mode line; a control-voltage generator coupled to sense the common mode line and provide a control voltage, the control voltage generator configured to adjust the control voltage to a voltage level such that a combined impedance of the first termination resistor, the first impedance-adjusting transistor, the second termination resistor, and the second impedance-adjusting transistor matches a specified impedance.

An illustrative short, high-rate communications link includes a serializer that provides a signal having a symbol rate of at least 10 GHz; and a deserializer that receives the signal via a printed circuit board (“PCB”) trace coupled to the serializer with a first impedance mismatch and coupled to the deserializer with a second impedance mismatch. At least one of the serializer and deserializer includes an equalizer that attenuates a frequency component of the signal at half of the symbol rate relative to a frequency component of the signal at one third of the symbol rate. Though such attenuation may reduce signal-to-noise ratio, an improved communications performance may nevertheless be achieved by suppression of signal reflections.

The present disclosure relates to devices and methods for detecting and preventing occurrence of a saturation state in a power amplifier. A power amplifier module can include a power amplifier including a cascode transistor pair. The cascode transistor pair can include a first transistor and a second transistor. The power amplifier module can include a current comparator configured to compare a first base current of the first transistor and a second base current of the second transistor to obtain a comparison value. The power amplifier module can include a saturation controller configured to supply a reference signal to an impedance matching network based on the comparison value. The impedance matching network can be configured to modify a load impedance of a load line in electrical communication with the power amplifier based at least in part on the reference signal.

A circuit is provide comprising a first input coupled to a transmit data input of a bus transceiver; and a first output coupled to a bus. The circuit is configured to be coupled in parallel with the bus transceiver. The circuit is further configured to, in response to a dominant to recessive transition on the transmit data input, lower an impedance of the bus.

A signal output circuit includes: a driver circuit including a variable current source and configured to output a multilevel signal; a replica circuit having a circuit configuration equivalent to the driver circuit; and a control circuit configured to control a characteristic of the driver circuit, based on an output signal of the replica circuit, wherein the replica circuit includes: a first replica circuit part configured to output first output signals having signal levels of a first subset of a plurality of signal levels corresponding to the multilevel signal; and a second replica circuit part configured to output second output signals having signal levels of a second subset of the plurality of signal levels, and the control circuit is configured to control a characteristic of the variable current source, based the first output signals and the second output signals.

A source injection mixer includes an FET, an IF matching circuit between an IF port and a gate of the FET, and that matches impedance of the IF port and impedance of the gate as viewed from the IF port, a shorting stub of which one end is connected to a source of the FET and another end is grounded, and shorter than ¼ of an electric length at a frequency of LO signals, an LO matching circuit between an LO port and the source of the FET, and that matches impedance of the LO port and impedance of the source as viewed from the LO port, and an RF matching circuit between an RF port and a drain of the FET, and that matches impedance of the RF port and impedance of the drain as viewed from the RF port.

A transmission device according to the disclosure includes a driver section that is able to transmit a data signal by using three or more predetermined number of voltage states and set voltages in each of the voltage states; and a control section that sets an emphasis voltage that is based on a transition among the predetermined number of the voltage states, and thereby causes the driver section to perform emphasis.

A semiconductor apparatus includes a calibration circuit, a selection circuit, and a data circuit. The calibration circuit generates a plurality of calibration signals by being coupled to a plurality of reference resistors. The selection circuit selects at least one signal among the plurality of calibration signals on the basis of an impedance setting signal. The data circuit sets an impedance based on the selected calibration signal.

An integrated circuit for generating an equalized signal, according to a channel, from serial data includes a shift register that extracts a symbol sequence from the serial data. A data storage stores values of an equalized digital signal corresponding to potential symbol sequences corresponding to a filter coefficient sequence. A lookup table outputs the equalized digital signal of a value corresponding to the extracted symbol sequence. A digital-to-analog converter (DAC) converts the equalized digital signal into the equalized signal. A controller refreshes the lookup table, based on at least one of values stored in the data storage and values included in the lookup table, in response to a control signal.

A transmission device according to the disclosure includes a driver section that is able to transmit a data signal by using three or more predetermined number of voltage states and set voltages in each of the voltage states; and a control section that sets an emphasis voltage that is based on a transition among the predetermined number of the voltage states, and thereby causes the driver section to perform emphasis.