A driver circuit of a PAM-N transmitting device transmits a PAM-N signal via a communication channel, wherein N is greater than 2, and the PAM-N signal has N signal levels corresponding to N symbols. A PAM-N receiving device receives the PAM-N signal. The PAM-N receiving device generates distortion information indicative of a level of distortion corresponding to inequalities in voltage differences between the N signal levels. The PAM-N receiving device transmits to the PAM-N transmitting device the distortion information indicative of the level of the distortion. The PAM-N transmitting device receives the distortion information. The PAM-N transmitting device adjusts one or more drive strength parameters of the driver circuit of the PAM-N transmitting device based on the distortion information.

A microwave generator includes a power supply, an output circuit, a feedback oscillator, a pulse controller, a signal combination circuit and a semiconductor amplifier. The power supply converts input voltage and input current into output voltage and output current. The output circuit generates a microwave signal to an output terminal of the microwave generator and a feedback signal according to the microwave signal. The feedback oscillator generates an oscillation signal according to the feedback signal. According to a reference signal, the pulse controller generates a pulse signal. According to the oscillation signal and pulse signal, the signal combination circuit generates a control signal. The semiconductor amplifier generates and adjusts an amplified signal according to the control signal. The output circuit generates the microwave signal according to the amplified signal. The output current is adjusted according to the amplified signal. Consequently, the input current and the input voltage are in phase.

A memory device as provided may apply a pulse amplitude modulation method to data (DQ) signal transmission/reception and may scale a DQ signal according to an operating frequency condition, so as to improve data transmission performance and effectively improve power consumption. The memory device includes a memory cell array, and a data input/output circuit configured to scale a DQ signal that includes data read from the memory cell array and output the scaled DQ signal. The data input/output circuit is configured to scale the DQ signal based on an n-level pulse amplitude modulation (PAMn) (where n is 4 or a greater integer) with a DQ parameter that corresponds an operating frequency condition and output the DQ signal. Other aspects include memory controllers that communicate with the memory devices, and memory systems that include the memory devices and memory controllers.

A memory device as provided may apply a pulse amplitude modulation method to data (DQ) signal transmission/reception and may scale a DQ signal according to an operating frequency condition, so as to improve data transmission performance and effectively improve power consumption. The memory device includes a memory cell array, and a data input/output circuit configured to scale a DQ signal that includes data read from the memory cell array and output the scaled DQ signal. The data input/output circuit is configured to scale the DQ signal based on an n-level pulse amplitude modulation (PAMn) (where n is 4 or a greater integer) with a DQ parameter that corresponds an operating frequency condition and output the DQ signal. Other aspects include memory controllers that communicate with the memory devices, and memory systems that include the memory devices and memory controllers.

A system includes a first encoder configured to receive first input bits and generate a first stream of first bits based on the first input bits, a bit generator configured to receive second inputs bits and generate a second stream of second bits based on the second input bits, and a PAM4 transmitter configured to receive the first stream of first bits and the second stream of second bits, and generate PAM4 symbols based at least on the first stream of first bits.

This document describes apparatuses and techniques for termination of a pulse amplitude modulation signal of a memory circuit. In various aspects, a memory circuit is implemented with a termination circuit that includes a power rail, a resistor, and a switch to couple the resistor between the power rail and a signal line of a memory interconnect. The power rail may be configured to provide power at a termination voltage that is nominally half of a voltage of another power rail from which a corresponding transmission circuit operates. This may be effective to enable termination of pulse amplitude modulation signals to the termination voltage instead of a higher voltage that corresponds to the power rail of the transmission circuit or a ground-referenced node. By so doing, use of the termination circuit may reduce power consumption and/or improve signal integrity of the memory circuit.

This document describes apparatuses and techniques for termination of a pulse amplitude modulation signal of a memory circuit. In various aspects, a memory circuit is implemented with a termination circuit that includes a power rail, a resistor, and a switch to couple the resistor between the power rail and a signal line of a memory interconnect. The power rail may be configured to provide power at a termination voltage that is nominally half of a voltage of another power rail from which a corresponding transmission circuit operates. This may be effective to enable termination of pulse amplitude modulation signals to the termination voltage instead of a higher voltage that corresponds to the power rail of the transmission circuit or a ground-referenced node. By so doing, use of the termination circuit may reduce power consumption and/or improve signal integrity of the memory circuit.

A receiver that receives a multi-level signal includes a pre-amplifier circuit, a slicer circuit and a decoder circuit. The pre-amplifier circuit generates a plurality of intermediate data signals based on an input data signal and a plurality of reference voltages. The slicer circuit generates a plurality of decision signals based on the plurality of intermediate data signals and a clock signal. The decoder circuit generates output data based on the plurality of decision signals. The pre-amplifier circuit includes a first circuit and a second circuit. The first circuit generates one of the plurality of intermediate data signals based on the input data signal and one of the plurality of reference voltages, and has a first structure. The second circuit generates another one of the plurality of intermediate data signals based on the input data signal and another one of the plurality of reference voltages, and has a second structure different from the first structure.

A transceiver includes a transmitter and a receiver coupled to each other through a first line and a second line. The transmitter transmits a first voltage signal of a second logic level or a fourth logic level, among a first logic level, the second logic level, a third logic level, and the fourth logic level, through the first line. The transmitter transmits a second voltage signal of the first logic level or the third logic level through the second line. The receiver generates an output signal having one of four values based on the first voltage signal and the second voltage signal.

A transceiver includes a transmitter and a receiver coupled to each other through a first line and a second line. The transmitter transmits a first voltage signal of a second logic level or a fourth logic level, among a first logic level, the second logic level, a third logic level, and the fourth logic level, through the first line. The transmitter transmits a second voltage signal of the first logic level or the third logic level through the second line. The receiver generates an output signal having one of four values based on the first voltage signal and the second voltage signal.