Certain aspects of the present disclosure are directed to a radio frequency digital-to-analog converter (RFDAC). The RFDAC generally includes a plurality of digital-to-analog (DAC) unit cells. At least one DAC unit cell is capable of being configured in an active state or in a sleep state. For the at least one DAC unit cell, an output impedance of the DAC unit cell in the active state is equal to an output impedance of the DAC unit cell in the sleep state.

An audio processing apparatus having an echo canceling mechanism is provided. An audio transmission circuit receives an input digital audio signal from an external device. A DAC circuit performs conversion according to the input digital audio signal to generate an output analog audio signal to an external display device for power amplification and playback. An ADC circuit performs analog-to-digital conversion on an amplified signal generated by a power amplification circuit and a received audio signal generated by an audio receiving device to generate an amplified digital signal and a received digital audio signal. A processor implements an echo canceling algorithm to perform echo cancellation according to the amplified digital signal and the received digital audio signal to generate an output digital audio signal to be transmitted to the external device through the audio transmission circuit.

In accordance with an embodiment, a method for digital-to-analog conversion includes: mapping a uniformly distributed input code to a non-uniformly distributed input code of a switched capacitor digital-to-analog converter (DAC), the non-uniformly distributed input code including a most significant code (MSC) and a least significant code (LSC); transferring a first charge from a set of DAC capacitors to a charge accumulator based on the MSC; forming a second charge based on the LSC; and transferring the second charge from the set of DAC capacitors to the charge accumulator, where each capacitor of the set of DAC capacitors is used for each value of the non-uniformly distributed input code, each capacitor of the set of DAC capacitors provides a same corresponding nominal charge within each value of the non-uniformly distributed input code, and where the same nominal charge is proportional to a value of the non-uniformly distributed input code.

In accordance with an embodiment, a method for digital-to-analog conversion includes: mapping a uniformly distributed input code to a non-uniformly distributed input code of a switched capacitor digital-to-analog converter (DAC), the non-uniformly distributed input code including a most significant code (MSC) and a least significant code (LSC); transferring a first charge from a set of DAC capacitors to a charge accumulator based on the MSC; forming a second charge based on the LSC; and transferring the second charge from the set of DAC capacitors to the charge accumulator, where each capacitor of the set of DAC capacitors is used for each value of the non-uniformly distributed input code, each capacitor of the set of DAC capacitors provides a same corresponding nominal charge within each value of the non-uniformly distributed input code, and where the same nominal charge is proportional to a value of the non-uniformly distributed input code.

A semiconductor device comprising at least one transmit path is provided. The transmit path comprises an input node for receiving a digital baseband signal. Further, the transmit path comprises digital mixer circuitry coupled to the input node and configured to generate an upconverted digital baseband signal by upconverting a frequency of the digital baseband signal. Additionally, the transmit path comprises Digital-to-Analog Converter (DAC) circuitry coupled to the digital mixer circuitry and configured to generate an analog radio frequency signal based on the upconverted digital baseband signal. The transmit path comprises first analog mixer circuitry coupleable to an output of the DAC circuitry, and second analog mixer circuitry coupleable to the output of the DAC circuitry. Further, the transmit path comprises a first output node coupleable to an output of the first analog mixer circuitry, and a second output node coupleable to an output of the second analog mixer circuitry.

A semiconductor device comprising at least one transmit path is provided. The transmit path comprises an input node for receiving a digital baseband signal. Further, the transmit path comprises digital mixer circuitry coupled to the input node and configured to generate an upconverted digital baseband signal by upconverting a frequency of the digital baseband signal. Additionally, the transmit path comprises Digital-to-Analog Converter (DAC) circuitry coupled to the digital mixer circuitry and configured to generate an analog radio frequency signal based on the upconverted digital baseband signal. The transmit path comprises first analog mixer circuitry coupleable to an output of the DAC circuitry, and second analog mixer circuitry coupleable to the output of the DAC circuitry. Further, the transmit path comprises a first output node coupleable to an output of the first analog mixer circuitry, and a second output node coupleable to an output of the second analog mixer circuitry.

An interface circuit that interfaces a digital-to-analog converter (DAC) to a vertical-cavity surface emitting laser. The apparatus includes a first cascode amplifier that receives as input positive and negative differential outputs of the DAC and provides a positive amplified output and a negative amplified output, and a second cascode amplifier having a positive input and a negative input. The positive input of the second cascode amplifier being coupled to the positive amplified output of the first cascode amplifier. The second cascode amplifier is configured to generate a positive amplified current and a negative amplified current at a negative amplified output. The positive amplified current and the negative amplified current are combined and a resulting output current is provided as input to an anode of the laser. A transformer is coupled between the negative amplified output of the first cascode amplifier and the negative input of the second cascode amplifier.

An interface circuit that interfaces a digital-to-analog converter (DAC) to a vertical-cavity surface emitting laser. The apparatus includes a first cascode amplifier that receives as input positive and negative differential outputs of the DAC and provides a positive amplified output and a negative amplified output, and a second cascode amplifier having a positive input and a negative input. The positive input of the second cascode amplifier being coupled to the positive amplified output of the first cascode amplifier. The second cascode amplifier is configured to generate a positive amplified current and a negative amplified current at a negative amplified output. The positive amplified current and the negative amplified current are combined and a resulting output current is provided as input to an anode of the laser. A transformer is coupled between the negative amplified output of the first cascode amplifier and the negative input of the second cascode amplifier.

A phase interpolator with a DAC outputting a first and second value responsive to a control code. A first current mirror generates a first current proportional to the first value. A second current mirror generates a second current proportional to the second value. A first FET pair comprising a first and second FET such that the source terminals of the first FET and the second FET are electrically connected and connect to the first current mirror. A second FET pair comprising a third and fourth FET such that the source terminals of the third FET and the fourth FET are electrically connected and connect to the second current mirror. A first terminal outputs a phase adjusted clock signal as compared to the clock signal, from the first FET and the third FET. A second terminal outputs an inverted phase adjusted clock signal, from the second FET and the fourth FET.

The present application provides a level shift circuit, an integrated circuit, and an electronic device. The level shift circuit comprises: an input module, configured to output a first control signal according to a first power supply voltage signal, first and second input voltages, inverted voltages of the first and second input voltages that received; a control voltage generation module, configured to receive the first control signal, and generate a plurality of node voltages according to the first control signal and a second power supply voltage signal; and output control modules, configured to generate first to fourth output signals according to the node voltages and the first power supply voltage signal, or generate fifth to eighth output signals according to the second power supply voltage signal and the node voltages.