Various embodiments of the present technology may comprise methods and apparatus for an amplifier circuit. Methods and apparatus for an amplifier circuit according to various aspects of the present invention may be utilized in a digital-to-analog converter. The amplifier circuit may comprise a first operational amplifier with a feedback circuit. The feedback circuit may comprise an inverting amplifier circuit.

Various embodiments of the present technology may comprise methods and apparatus for an amplifier circuit. Methods and apparatus for an amplifier circuit according to various aspects of the present invention may be utilized in a digital-to-analog converter. The amplifier circuit may comprise a first operational amplifier with a feedback circuit. The feedback circuit may comprise an inverting amplifier circuit.

A D/A conversion circuit includes: an output terminal connected to an operational amplifier connected to a quantization circuit; a DAC capacitor; a selection switch switching among reference, first and second voltages to apply to the DAC capacitor as an analog potential; a ground switch connecting the DAC capacitor to a ground; and an output switch connecting the DAC capacitor to the output terminal. In a first period, the selection switch selects one of the reference, first and second voltages according to a quantization result value from the quantization circuit, and connects the one to the DAC capacitor, and the ground switch turns on to charge the DAC capacitor. In a second period, the selection switch selects another one of the first and second voltages, and connects the another one to the DAC capacitor, and the output switch turns on to output the analog potential to the output terminal.

A D/A conversion circuit includes: an output terminal connected to an operational amplifier connected to a quantization circuit; a DAC capacitor; a selection switch switching among reference, first and second voltages to apply to the DAC capacitor as an analog potential; a ground switch connecting the DAC capacitor to a ground; and an output switch connecting the DAC capacitor to the output terminal. In a first period, the selection switch selects one of the reference, first and second voltages according to a quantization result value from the quantization circuit, and connects the one to the DAC capacitor, and the ground switch turns on to charge the DAC capacitor. In a second period, the selection switch selects another one of the first and second voltages, and connects the another one to the DAC capacitor, and the output switch turns on to output the analog potential to the output terminal.

Digital to analog converter architectures are disclosed that enable the binary scaling of transistor sized to be replaced by transistors of substantially the same size. This significantly reduced the size of the Digital to Analog converter on a wafer. As the currents from the lesser bits of the converter may be very small indeed, some of the transistors are operated in a regime where the gate-source voltage applied to the transistor is below the threshold voltage for the device, the threshold voltage generally being regarded as marking the onset of significant conduction through a field effect transistor.

The present disclosure relates to an apparatus and a method for cancelling echo by an electronic device. Here, a method of operating an electronic device includes converting a first digital signal related to a sound to be output through a plurality of speakers into a first analog signal; outputting the converted first analog signal as a sound using at least a part of the plurality of speakers; filtering at least a part of the converted first analog signal and/or the output sound and then generating a second analog signal; and outputting the second analog signal as another sound using at least another part of the plurality of speakers.

The present disclosure relates to an apparatus and a method for cancelling echo by an electronic device. Here, a method of operating an electronic device includes converting a first digital signal related to a sound to be output through a plurality of speakers into a first analog signal; outputting the converted first analog signal as a sound using at least a part of the plurality of speakers; filtering at least a part of the converted first analog signal and/or the output sound and then generating a second analog signal; and outputting the second analog signal as another sound using at least another part of the plurality of speakers.

A method includes receiving samples of digital to analog converter (DAC), partitioning the samples to unit-DACs based upon previous partitions of inputs to the unit-DACs to cancel out integrated non-linearities of outputs of the DAC caused by the gain mismatches of the unit-DACs, including partitioning samples of DAC input to the unit-DACs through a recursive nth order partitioning algorithm. The algorithm includes, for each DAC input, determining a first partition of the DAC input that would cancel an (n1)th order previously integrated non-linearity, adding an equivalent DAC input of the first partition to the DAC input to obtain a total DAC input, using a first order application of the total DAC input to the inputs of the unit-DACs to yield a second partition of DAC input, summing the first and second partitions generate a final partition, and, based on the final partition, computing non-linearity remainders at each order of integration.

A method includes receiving samples of digital to analog converter (DAC), partitioning the samples to unit-DACs based upon previous partitions of inputs to the unit-DACs to cancel out integrated non-linearities of outputs of the DAC caused by the gain mismatches of the unit-DACs, including partitioning samples of DAC input to the unit-DACs through a recursive nth order partitioning algorithm. The algorithm includes, for each DAC input, determining a first partition of the DAC input that would cancel an (n1)th order previously integrated non-linearity, adding an equivalent DAC input of the first partition to the DAC input to obtain a total DAC input, using a first order application of the total DAC input to the inputs of the unit-DACs to yield a second partition of DAC input, summing the first and second partitions generate a final partition, and, based on the final partition, computing non-linearity remainders at each order of integration.

Embodiments provide an audio amplifier circuit with integrated (built-in) filter (e.g., a digital-to-analog converter (DAC) filter). The audio amplifier circuit may have a non-flat (e.g., low-pass) closed loop frequency response. The audio amplifier circuit may include a low pass filter coupled between an input terminal that receives the input analog audio signal and the input of the gain stage of the amplifier. In some embodiments, additional impedance networks may be included to produce a desired low-pass filter response, such as a second order filter, a third order filter, and/or another suitable filter response. Other embodiments may be described and/or claimed.