An analog-to-digital converter (ADC) includes a first operator configured to subtract an analog value from an analog signal; an amplifier configured to amplify an output of the first selector; a filter configured to filter an output of the amplifier; a quantizer configured to generate a digital bit stream from an output of the filter; and a digital-to-analog converter (DAC) configured to output the analog value according to the digital bit stream.

A Sigma-Delta analog to digital converter (ADC) is described. The Sigma-Delta ADC includes a series arrangement of a gain tracker, a first discrete-time integrator stage and a quantizer between an ADC input and an ADC output. The Sigma-Delta ADC includes a digital to analog converter (DAC) having a DAC input and a DAC output connected to the gain tracker. The Sigma-Delta analog to digital converter includes a controller having a control input connected to the quantizer output. The controller provides a digital input to the DAC input and provides a gain control signal to the gain tracker.

A transceiver system includes a transmitter circuit having a line driver with a programmable signal level to generate a transmit signal for transmission in an automotive environment over an unshielded-twisted pair (UTP) cable. The transceiver system further includes a physical layer (PHY) receiver. The PHY receiver includes a high-pass filter (HPF), an adaptive feed-forward equalizer (FFE) block and a noise aware adaptation block. The HPF rejects transient noise of a received signal, and the FFE block receives a digital signal and adaptively filters out narrowband continuous wave (CW) noise using an adaptation signal. The digital signal is based on the received signal, and the noise aware adaptation block receives an error signal and generates the adaptation signal. The error signal is generated based on an equalized signal of the FFE block and an estimated signal. The combined transmit and receive circuitry allow lowering emission while rejecting strong receiver automotive noises.

A system has a digital-to-analog converter; a reference signal coupled to the digital-to-analog converter; a differential amplifier for applying gain, and for generating output signals as a function of sampled input signals, the reference signal, digital codes, and the gain applied by the differential amplifier coupled to the digital-to-analog converter; and a multi-bit successive-approximation register for determining the digital codes in successive stages coupled to the differential amplifier; and the gain applied by the differential amplifier is corrected based on previously determined digital codes.

A circuit comprises a first amplifier coupled to a first and a second node; a differential capacitive load coupled to the first and the second node, the differential capacitive load coupled between drains of transistors in a cross coupled transistor circuit; a current mirror coupled to a source of each transistor; and a capacitor coupled between the sources of the transistors. A plurality of amplifiers can be coupled to the differential capacitive load, wherein each amplifier comprises a clock-less pre-amplifier of a comparator. The amplifiers may be abutted to one another such that an active transistor of a first differential stage in a first amplifier behaves as a dummy transistor for an adjacent differential stage in a second amplifier.

An apparatus and a method are provided. The apparatus includes an analog-to-digital converter (ADC) driver; and an ADC that is electrically coupled to the ADC driver. The method includes setting, by an analog-to-digital converter (ADC) driver, a desired common-mode control value based on the held voltage; and setting, by the ADC driver, a desired gain control value based on the held voltage.

An A/D converter includes an A/D conversion circuit for converting an analog output signal into a digital signal, and a control circuit for controlling the A/D conversion circuit. The control circuit acquires a digital signal of a first bit indicating which level regions the voltage level of the analog output signal corresponds to in accordance with a first conversion operation by the A/D conversion circuit, sets a reference voltage corresponding to the level region based on the first bit, amplifies the difference voltage between the analog output signal and the reference voltage to correspond to the A/D conversion input range of the A/D conversion circuit, outputs an amplified analog signal, acquires a digital signal of a second bit indicating the voltage level of the amplified analog signal in accordance with a second conversion operation by the A/D conversion circuit, and synthesizes the first bit and the second bit.

Disclosed is a sound recording circuit capable of adjusting microphone sensitivity and preventing sound cracks caused by overly loud sound. The sound recording circuit includes: a microphone bias circuit configured to provide a bias voltage for a microphone circuit; an AC coupling capacitor configured to output an analog input signal according to a microphone signal of the microphone circuit; an analog amplifier circuit configured to output an analog output signal according to the analog input signal; an analog-to-digital converter configured to output a digital input signal according to the analog output signal; a digital amplifier circuit configured to output a digital output signal according to the digital input signal; and a signal detector configured to control an analog gain of the analog amplifier circuit, a digital gain of the digital amplifier circuit, and the bias voltage of the microphone bias circuit.

A transceiver system includes a transmitter circuit having a line driver with a programmable signal level to generate a transmit signal for transmission in an automotive environment over an unshielded-twisted pair (UTP) cable. The transceiver system further includes a physical layer (PHY) receiver. The PHY receiver includes a high-pass filter (HPF), an adaptive feed-forward equalizer (FFE) block and a noise aware adaptation block. The HPF rejects transient noise of a received signal, and the FFE block receives a digital signal and adaptively filters out narrowband continuous wave (CW) noise using an adaptation signal. The digital signal is based on the received signal, and the noise aware adaptation block receives an error signal and generates the adaptation signal. The error signal is generated based on an equalized signal of the FFE block and an estimated signal. The combined transmit and receive circuitry allow lowering emission while rejecting strong receiver automotive noises.

The disclosed technology relates to a method for improving performance of a feedback circuit comprising an amplifier and a feedback network, wherein the feedback circuit has at least one tunable component. In one aspect, the method comprises measuring first amplitude values at an input of the amplifier and second amplitude values at an output of the amplifier, estimating a linear open-loop gain of the amplifier based on both the amplitude values, estimating a linear finite gain error based on the estimated gain and the second amplitude values, subtracting the linear finite gain error from the first amplitude values to derive a set of samples containing second error information, deriving an signal-to-noise-plus-distortion ratio estimate based on the variance of the set of samples and a variance of the second amplitude values, and adjusting the feedback circuit in accordance with the signal-to-noise-plus-distortion ratio estimate.