A digital/analog converter (DAC) includes a reference current generator including an internal resistor, and configured to generate reference current according to a resistance value of the internal resistor and a reference voltage, a digital gain block configured to generate a calibrated digital input signal that is obtained by adjusting a digital gain of a digital input signal based on a ratio between a reference resistance value and a resistance value of the internal resistor, and a conversion circuit configured to convert the calibrated digital input signal into an analog output signal, based on the reference current.

An analog-to-digital converter (ADC) is described. This ADC includes a conversion circuit with multiple bit-conversion circuits. During operation, the ADC may receive an input signal. Then, the conversion circuit may asynchronously perform successive-approximation-register (SAR) analog-to-digital conversion of the input signal using the bit-conversion circuits, where the bit-conversion circuits to provide a quantized representation of the input signal. For example, the bit-conversion circuits may asynchronously and sequentially perform the SAR analog-to-digital conversion to determine different bits in the quantized representation of the input signal. Moreover, the ADC may selectively perform self-calibration of a global delay of the bit-conversions circuits. Note that the timing self-calibration may be iterative and subject to a constraint that a maximum conversion time is less than a target conversion time.

A two-capacitor digital-to-analog converter circuit having circuitry to compensate for an unwanted capacitance is disclosed. The converter is configured to generate an average voltage on two capacitors for a sequence of bits in a digital word so that when the final bit is reached, the average voltage corresponds to an analog level of the digital word. The converter is configured to input and average the voltage on the two capacitors using different modes to minimize the effects of capacitor mismatch and switching capacitance on the accuracy of the conversion. The converter includes a buffer amp that has an input capacitance that can affect the conversion. Accordingly, the converter further includes capacitance compensation circuitry configured to provide a replica input capacitance that can be charged and discharged according to the bits of the digital word and coupled to the input capacitor to prevent the input capacitance from affecting the conversion.

An oscillator-based sensor interface circuit includes first and second input nodes arranged to receive first and second electrical signals representative of an electrical quantity, respectively; an analog filter; a first oscillator arranged to receive a first oscillator input signal and a second oscillator different from the first oscillator and arranged to receive a second oscillator input signal; a comparator arranged to compare signals coming from the first and second oscillators; a first feedback element arranged to receive a representation of the digital comparator output signal and to convert the representation into a first feedback signal to be applied to the oscillation means; a digital filter arranged to yield an output signal, being an filtered version of the digital comparator output signal; a second feedback element arranged to receive the output signal and to convert the output signal into a second feedback signal.

A segmented digital-to-analog converter (DAC) includes DAC segments, an overrange DAC, and a dither control circuit. Each DAC segment includes a plurality of DAC cells for generating an analog output signal based on input data to each DAC segment. The overrange DAC generates an analog output signal based on a control signal. The dither control circuit adds a dither to first input data supplied to a higher-order DAC segment, subtract a portion of the dither from second input data supplied to a lower-order DAC segment, and generate the control signal for subtracting a remaining portion of the dither from an output of the segmented DAC in an analog domain. The dither added to the first input data may be one of +1, 0, and −1 and the portion of the dither subtracted from the second input data may be a half of the dither added to the first input data.

A ramp voltage generator includes: a ramping cell array including a plurality of ramping current cells; a calibration cell array including a plurality of calibration current cells; and a current-voltage converter suitable for converting a current supplied from activated ramping current cells among the ramping current cells and activated calibration current cells among the calibration current cells into a voltage to generate a ramp voltage.

A control circuit of a pipeline analog-to-digital converter (ADC) is provided. The pipeline ADC includes a multiplying digital-to-analog converter (MDAC) which includes a capacitor. The control circuit includes six switches and two buffer circuits. The first and second switches are respectively coupled between one end of the capacitor and the first and second reference voltages. The output terminals of the first and second buffer circuits are respectively coupled to the first and second switches. The input terminal of the first buffer circuit is coupled to the third reference voltage through the third switch, or receives a control signal through the fifth switch. The input terminal of the second buffer circuit is coupled to the fourth reference voltage through the fourth switch, or receives the control signal through the sixth switch. The first and second reference voltages are different, and the first and second switches are not turned on simultaneously.

An analog-to-digital converter (ADC) is described. This ADC includes a conversion circuit with multiple bit-conversion circuits. During operation, the ADC may receive an input signal. Then, the conversion circuit may asynchronously perform successive-approximation-register (SAR) analog-to-digital conversion of the input signal using the bit-conversion circuits, where the bit-conversion circuits to provide a quantized representation of the input signal. For example, the bit-conversion circuits may asynchronously and sequentially perform the SAR analog-to-digital conversion to determine different bits in the quantized representation of the input signal. Moreover, the ADC may selectively perform self-calibration of a global delay of the bit-conversions circuits. Note that the timing self-calibration may be iterative and subject to a constraint that a maximum conversion time is less than a target conversion time.

A buffer circuit includes a first differential signal input, a second differential signal input, a first source follower circuit, and a second source follower circuit. The first source follower circuit includes a first signal output, and a first input transistor. The first input transistor is coupled to the first differential signal input, and is configured to drive the first signal output. The second source follower circuit includes a second signal output, a second input transistor, and a cascode transistor. The second input transistor is coupled to the second differential signal input, and is configured to drive the second signal output. The cascode transistor is coupled to the second input transistor and the first signal output, and is configured to compensate for non-linearity of the second input transistor based on an output signal provided at the first signal output.

An analog-to-digital (ADC) converter system and method of using the system that can be used in low power situations. The converter can periodically or recurrently turn off a reference standard in order to conserve power and instead using a stable supply source as a reference voltage. A precise conversion for signal from the analog to the digital domain while maintaining a low quiescent current.