A microphone system includes: a microphone including a microphone output terminal and a microphone GND terminal, the microphone being configured to output, as an input sound signal, a voltage signal exhibiting a change in voltage between the microphone output terminal and the microphone GND terminal depending on an input sound; an A/D converting unit mounted on a first circuit board and configured to perform digital conversion on the input sound signal that is input; and a power supply circuit mounted on a second circuit board connected to the first circuit board via a pair of power supply lines, and configured to feed DC power to the A/D converting unit via the pair of power supply lines. The microphone outputs the input sound signal to the A/D converting unit via a pair of first signal lines different from the pair of power supply lines.

Methods and devices are provided for circuits. One device includes an adjustment circuit having an adjustable resistor for modifying a resistance value of a resistive device, the adjustment circuit connected to an adjustment terminal of the resistive device. The resistance value of the adjustable resistor changes, when a voltage or charge on the adjustment terminal of the adjustable resistor is changed. The adjustable resistor is a phase change element with an adjusting terminal to which different voltage values are applied for adjusting a conversion device threshold value.

Techniques for improving a power supply accuracy of a precision data converter system, such as analog-to-digital converter circuits (ADCs) and digital-to-analog converter circuits (DACs). Improving the power supply accuracy can enable a reference voltage to be as large as possible, thereby increasing the signal-to-noise-ratio (SNR). The techniques can also simplify power supply sequencing requirements for the data converter system.

Techniques for improving a power supply accuracy of a precision data converter system, such as analog-to-digital converter circuits (ADCs) and digital-to-analog converter circuits (DACs). Improving the power supply accuracy can enable a reference voltage to be as large as possible, thereby increasing the signal-to-noise-ratio (SNR). The techniques can also simplify power supply sequencing requirements for the data converter system.

A digital-to-analog converter includes a resistor ladder, a first switch and a protection circuit. The first switch includes a first terminal and a second terminal that are respectively coupled to a rung of the resistor ladder and a reference voltage node. The protection circuit is coupled to the reference voltage node and to a reference voltage input terminal. The protection circuit includes a second switch, a third switch, and a fourth switch. First and second terminals of the second switch are respectively coupled to the reference voltage node and the reference voltage input terminal. First and second terminals of the third switch are respectively coupled to the reference voltage node and a reference voltage feedback terminal. The first and second terminals of the fourth switch are respectively coupled to the reference voltage input terminal and the reference voltage feedback terminal.

A digital-to-analog converter comprises a plurality of first digital-to-analog converter cells configured to generate a first analog signal based on first digital data, wherein the first digital-to-analog converter cells of the plurality of first digital-to-analog converter cells are coupled to a first output node for coupling to a first load. Further, the digital-to-analog converter comprises a plurality of second digital-to-analog converter cells configured to generate one or more second analog signals based on second digital data, wherein the second digital-to-analog converter cells of the plurality of second digital-to-analog converter cells are coupled to one or more second output nodes, and wherein the plurality of first digital-to-analog converter cells and the plurality of second digital-to-analog converter cells are coupled to a power supply node for coupling to a mutual power supply.

The present invention provides a reference voltage generating circuit. The reference voltage generating circuit includes a charge supply circuit providing a first reference voltage during a first period; and a voltage supply circuit providing a second reference voltage during a second period. The voltage supply circuit does not provide the second reference voltage during the first period.

An integrated circuit is provided that includes an output stage circuit. The output stage circuit includes an input node for receiving a digital input signal, a supply voltage node for receiving a supply voltage signal, a digital to analog convertor for converting the digital signal, an amplifier for amplifying the converted signal, a first/second and optionally third voltage regulator generating a first/second and optionally third voltage signal, and a greatest-voltage selector circuit for providing power to the amplifier. Two different voltages are provided to the DAC. The output signal can be a SENT signal. The circuit is highly robust against power-interruptions and EMI.

Methods and systems 10 are provided for circuits. One method is for increasing device threshold voltage distribution of a plurality of devices of a circuit. The method includes adjusting a device threshold voltage of the plurality of devices by different amounts; and selecting a subset of the plurality of devices with adjusted device threshold voltage by a device selection module for performing a function associated with the circuit. In one aspect, a system for device threshold voltage adjustment is provided. The system includes a sensor module for sensing one or more of temperature and voltage values of a die having a plurality of devices for a circuit; and a threshold temperature and voltage compensation module for receiving an input value from the sensor module to compensate variation in a device threshold voltage caused by changes of one or more of temperature and voltage of the die.

The present invention provides a device for processing digital signals. The device comprises a digital signal source configured to output codewords, a converter circuit configured to generate an output signal based on a first codeword received from the digital signal source, and a feed forward circuit configured to generate an output current based on a second codeword received from the digital signal source. The output current generated by the feed forward circuit is connected to a current supply of the converter circuit. The digital signal source is configured to generate the second codeword based on the first codeword in order to compensate for variations of a supply current of the converter circuit.