Embodiments provide a pre-distortion circuit and apparatus, a method and computer program for pre-distorting, a transmitter, a radio transceiver, a communication device, a mobile transceiver, a base station transceiver and a storage. The pre-distortion circuit (10) is configured for a digital quadrature signal. The pre-distortion circuit (10) comprises a first input (12) for an inphase component of the quadrature signal and a second input (14) for a quadrature component of the quadrature signal. The pre-distortion circuit 10 comprises a signal processing circuit (16) configured to determine whether polarities of the inphase component and quadrature component are equal, and to determine pre-distortion coefficients based on the amplitude of the inphase component, the amplitude of the quadrature component, and based on whether the polarities are equal.

A digital-to-analog conversion circuit, a digital-to-analog conversion method, and a display device are provided. The digital-to-analog conversion circuit includes a first digital-to-analog conversion sub-circuit and a second digital-to-analog conversion sub-circuit. The second digital-to-analog conversion sub-circuit includes least-significant-bit voltage selection modules whose quantity is a, a weighed summation operational amplifier, switching control modules whose quantity is a and energy storage modules whose quantity is a. The weighted summation operational amplifier includes a reverse-phase input end, an operational amplification output end, and same-phase input ends whose quantity is a. The reverse-phase input end is connected to the operational amplification output end, and a is an integer greater than 1. The weighted summation operational amplifier is configured to perform weighted summation on voltages inputted by the a same-phase input ends at a digital-to-analog conversion stage to acquire an analog voltage, and output the analog voltage via the operational amplification output end.

A receiver or transmitter circuit includes a signal propagation path between a radio-frequency (RF) signal node and a baseband processing circuit. Variable gain circuitry is configured to vary a gain applied to a signal propagating between the RF signal node and the baseband processing circuit. The variable gain circuitry varies the gain via first, coarse steps as well as via second, fine steps. This facilitates fine matching of the gains experienced by signals propagating over the in-phase and the quadrature branches in the transmitter and/or receiver circuit.

A receiver or transmitter circuit includes a signal propagation path between a radio-frequency (RF) signal node and a baseband processing circuit. Variable gain circuitry is configured to vary a gain applied to a signal propagating between the RF signal node and the baseband processing circuit. The variable gain circuitry varies the gain via first, coarse steps as well as via second, fine steps. This facilitates fine matching of the gains experienced by signals propagating over the in-phase and the quadrature branches in the transmitter and/or receiver circuit.

A sigma delta modulator device includes a sampling circuit, a digital to analog converter circuit, an integrator circuit, and an analog to digital converter circuit. The sampling circuit is configured to sample an input signal, in order to generate a first signal. The digital to analog converter circuit is configured to convert a first digital signal to be a combination of a first reference voltage and a common mode voltage, in order to generate a second signal, in which the first reference voltage is one of a positive reference voltage and a negative reference voltage. The integrator circuit is configured to perform integration according to the first signal and the second signal, in order to generate a third signal. The analog to digital converter circuit is configured to quantize the third signal to generate an output signal, and to generate the first digital signal according to the output signal.

A digital-to-analog converter (“DAC”) converts digital image data into analog image signals. The DAC includes a stage outputting different voltages to a first output terminal and a second output terminal based on a voltage supplied to a first input terminal, a voltage supplied to a second input terminal, and a first input bit. The stage includes a switch circuit including switches that are alternately turned on by a control signal, and outputting an intermediate output voltage to a third output terminal based on a first input voltage supplied to the first input terminal and a second input voltage supplied to the second input terminal, and a selector outputting one of the first input voltage and the second input voltage, and the intermediate output voltage.

A digital-analog converter of the disclosure converts digital image data to generate analog data signals. The digital-analog converter includes a voltage divider which generates a plurality of gamma reference voltages based on a first reference voltage and a second reference voltage; a global ramp including a plurality of gamma decoders which generates a plurality of global gamma voltages based on the gamma reference voltages; a decoder which selects one of the global gamma voltages according to the digital image data to generate the analog data signals; and a ramp controller which turns off at least some of the gamma decoders based on the digital image data.

A digital-analog converter of the disclosure converts digital image data to generate analog data signals. The digital-analog converter includes a voltage divider which generates a plurality of gamma reference voltages based on a first reference voltage and a second reference voltage; a global ramp including a plurality of gamma decoders which generates a plurality of global gamma voltages based on the gamma reference voltages; a decoder which selects one of the global gamma voltages according to the digital image data to generate the analog data signals; and a ramp controller which turns off at least some of the gamma decoders based on the digital image data.

Disclosed is an output buffer circuit for a display driving apparatus, which generates an output voltage by using a bias current controlled by digital-to-analog conversion for interpolation data, the output buffer circuit including a decoder configured to output control data obtained by decoding interpolation data, and an output circuit configured to output an output voltage by using a bias current having the amount of current controlled by digital-to-analog conversion for the control data.

Some disclosed embodiments relate, generally, to shaping a waveform of a reference signal used by a driver of a touch sensor to limit electromagnetic emissions (EME) emitted by a touch sensor during a sensing operation. Some disclosed embodiments relate, generally, to a DAC referenced touch sensor driver and controlling an amount of EME emitted at a touch sensor using shapes of reference signals used by a touch detector to detect touches at the touch sensor. Some disclosed embodiments relate, generally, to compensating for effects of foreign noise at a touch sensor. And more specifically, to changing a shape of a reference signal based on a change to a sampling rate made to compensate for foreign noise.