Systems, apparatuses, and methods for performing digital pre-distortion compensation of digital-to-analog converter non-linearity are described. A correction circuit receives a digital input word and couples a portion of the most significant bits (MSB's) of the digital input word to a correction lookup table (LUT). A correction value is retrieved from a correction LUT entry that matches the MSB's of the digital input word. Next, the correction value is added to the original digital input word in the digital domain. Then, the sum generated by adding the correction value to the original digital input word is optionally clipped if the sum exceeds the DAC core's input range. Next, the DAC core converts the sum into an analog value that is representative of the digital input word. The above approach helps to reduce non-linearities introduced by the DAC core in an energy-efficient manner by performing a correction in the digital domain.

According to an embodiment, a digital microphone includes an analog-to-digital converter (ADC) for receiving an analog input signal; a DC blocker component coupled to the ADC; a digital low pass filter coupled to the DC block component; and a nonlinear compensation component coupled to the digital low pass filter for providing a digital output signal.

Systems, apparatuses, and methods for performing digital pre-distortion compensation of digital-to-analog converter non-linearity are described. A correction circuit receives a digital input word and couples a portion of the most significant bits (MSB's) of the digital input word to a correction lookup table (LUT). A correction value is retrieved from a correction LUT entry that matches the MSB's of the digital input word. Next, the correction value is added to the original digital input word in the digital domain. Then, the sum generated by adding the correction value to the original digital input word is optionally clipped if the sum exceeds the DAC core's input range. Next, the DAC core converts the sum into an analog value that is representative of the digital input word. The above approach helps to reduce non-linearities introduced by the DAC core in an energy-efficient manner by performing a correction in the digital domain.

The present application discloses an ADC (10). The ADC has an A/D conversion operation mode and a measurement operation mode. The ADC includes an input terminal (100), a DAC (104), and an output terminal (102). The input terminal is configured to receive an analog signal. The output terminal is configured to output a digital signal. The DAC includes a plurality of D/A conversion units. When the ADC operates in the A/D conversion operation mode, the ADC is configured to convert the analog signal into the digital signal, and when the ADC operates in the measurement operation mode, the digital signal related to a ratio of a capacitance of the D/A conversion unit to be measured to a total capacitance of the plurality of D/A conversion units.

A sigma-delta modulator includes an N-bit quantization circuit that generates a stream of N-bit code words and a feedback signal path with an N-bit DAC circuit, having a non-ideal operation due to mismatch error, that converts the stream of N-bit code words to generate a feedback signal. A digital DAC copy circuit provides a digital replication of the N-bit DAC circuit. The digital replication accounts for the non-ideal operation of the N-bit DAC circuit 126 due to mismatch error, and converts the stream of N-bit code words to generate a stream of P-bit code words, where P>N, that are functionally equivalent to the feedback signal output from the N-bit DAC circuit.

A sigma-delta modulator includes an N-bit quantization circuit that generates a stream of N-bit code words and a feedback signal path with an N-bit DAC circuit, having a non-ideal operation due to mismatch error, that converts the stream of N-bit code words to generate a feedback signal. A digital DAC copy circuit provides a digital replication of the N-bit DAC circuit. The digital replication accounts for the non-ideal operation of the N-bit DAC circuit 126 due to mismatch error, and converts the stream of N-bit code words to generate a stream of P-bit code words, where P>N, that are functionally equivalent to the feedback signal output from the N-bit DAC circuit.

The present application discloses an ADC (10). The ADC has an A/D conversion operation mode and a measurement operation mode. The ADC includes an input terminal (100), a DAC (104), and an output terminal (102). The input terminal is configured to receive an analog signal. The output terminal is configured to output a digital signal. The DAC includes a plurality of D/A conversion units. When the ADC operates in the A/D conversion operation mode, the ADC is configured to convert the analog signal into the digital signal, and when the ADC operates in the measurement operation mode, the digital signal related to a ratio of a capacitance of the D/A conversion unit to be measured to a total capacitance of the plurality of D/A conversion units.

A correction method and a correction circuit for a sigma-delta modulator (SDM) are disclosed. The SDM includes a loop filter, a quantizer, and a digital-to-analog converter (DAC), and the loop filter includes a resonator. The correction circuit includes a memory and a control circuit. The memory stores multiple program instructions. The control circuit executes the program instructions to correct the SDM. The correction procedure of the SDM includes the following steps: inputting a test signal to the SDM; obtaining a signal characteristic value of an output signal of the SDM; and adjusting the resonator according to the signal characteristic value.

A method for calibrating a multi-bit Delta-Sigma modulator is disclosed herein. The method includes at least one main multi-bit digital-analogue converter in a return loop for generating a return signal subtracted from an input of the modulator. The main converter includes a plurality of elementary source cells at least some of which, referred to as active cells, are associated with the various input bits of the converter for generating the return signal. The output level of these active source cells is adjustable under the action of a matching signal that comes from a calibration circuit receiving an output signal from the modulator at its input. The calibration circuit includes a generator of a calibration sequence.

A modulator includes an analog integrator including an analog circuit and a quantizer quantizing its output signal. An external input signal is input thereto. A modulator is coupled to the latter stage of the modulator, and includes a quantizer. A probe signal generation circuit injects a probe signal to the modulator. An adaptive filter searches for a transfer function of the modulator by observing an output signal of the quantizer in accordance with a probe signal. Another adaptive filter searches for a transfer function of the modulator by observing an output signal of the quantizer in accordance with the probe signal. A noise cancel circuit cancels a quantization error generated by the quantizer using search results of the adaptive filters.