Abstract: A digital-to-analog converter (DAC) device includes a DAC circuitry, a calibration circuitry, and a randomization circuitry. The DAC circuitry includes a first DAC circuit and a second DAC circuit. The first DAC circuit is configured to generate a first signal according to least significant bits of an input signal. The second DAC circuit is configured to output a second signal. The calibration circuitry is configured to compare the first signal with the second signal, in order to calibrate the second DAC circuit. The randomization circuitry is configured to randomize most significant bits of the input signal, in order to generate first control signals, in which the second DAC circuit is further configured to generate the second signal according to the most significant bits or the first control signals.

Abstract: A self-test circuit and a self-test method for a comparator are provided. A first output terminal of the comparator is coupled to an input terminal of a first inverter, and a second output terminal of the comparator is coupled to an input terminal of a second inverter. The comparator operates in a reset phase or a comparison phase according to a clock. The self-test method includes steps of: coupling the first output terminal and the second output terminal so that the comparator enters a test mode; and in the test mode, controlling the comparator to operate in the reset phase or the comparison phase according to the clock. In the test mode, the first output terminal and the second output terminal have substantially the same voltage.

Abstract: This invention discloses a multiplying digital-to-analog converter (MDAC) applied to a pipelined analog-to-digital converter (pipelined ADC). The MDAC includes an operational amplifier. The MDAC samples a differential input signal in a sampling phase and performs subtraction and multiplication operations in an amplification phase according to a first reference voltage and a second reference voltage. The common-mode voltage of the first reference voltage and the second reference voltage is not substantially equal to the common-mode voltage of the differential input signal; and/or the voltage difference between the first reference voltage and the second reference voltage is not substantially equal to one half of an allowed maximum peak-to-peak value of the differential input signal. One of the first reference voltage and the second reference voltage can be ground.

Abstract: This invention discloses a multiplying digital-to-analog converter (MDAC) applied to a pipelined analog-to-digital converter (pipelined ADC). The MDAC includes an operational amplifier. The MDAC samples a differential input signal in a sampling phase and performs subtraction and multiplication operations in an amplification phase according to a first reference voltage and a second reference voltage. The common-mode voltage of the first reference voltage and the second reference voltage is not substantially equal to the common-mode voltage of the differential input signal; and/or the voltage difference between the first reference voltage and the second reference voltage is not substantially equal to one half of an allowed maximum peak-to-peak value of the differential input signal. One of the first reference voltage and the second reference voltage can be ground.

Abstract: Disclosed is a bit error rate (BER) forecast circuit for successive approximation register analog-to-digital conversion. The BER forecast circuit includes an N bits successive approximation register analog-to-digital converter (N bits SAR ADC) and an estimation circuit. The N bits SAR ADC is configured to carry out a regular operation at least N times and an additional operation at least X time(s) in one cycle of conversion time, in which the N is an integer greater than 1 and the X is an integer not less than zero. The estimation circuit is configured to generate a test value according to total times the N bits SAR ADC carrying out the additional operation in Y cycles of the conversion time, in which the Y is a positive integer and the test value is related to the bit error rate of the N bits SAR ADC.

Abstract: A calibration circuit and calibration method for a successive approximation register analog-to-digital converter (SAR ADC) are disclosed. The SAR ADC includes a comparator and generates a digital code. The calibration method includes the following steps: (a) creating a voltage difference between two inputs of the comparator, with the absolute value of the voltage difference being smaller than or equal to the absolute value of the voltage corresponding to the least significant bit (LSB) of the digital code; (b) updating a count value according to whether a timer of the SAR ADC issues a time-out signal, the timer issuing the time-out signal after a delay time has elapsed; (c) repeating steps (a) through (b) a predetermined number of times; (d) calculating a probability based on the predetermined number of times and the count value; and (e) adjusting the delay time according to the probability.

Abstract: A sample-and-hold amplifier includes: a switched capacitor network for conducting a sample -and-hold operation on an input signal to generate a first signal; and an operational amplifier coupled with the switched capacitor network and including multiple candidate capacitors; wherein the operational amplifier is arranged to operably generate an output signal based on the first signal, and to operably switch coupling relationship of the multiple candidate capacitors based on the magnitude of the input signal, so that only a portion of the multiple candidate capacitors could be participated in the generation of the output signal at a time.

Abstract: An operational amplifier includes: a first gain stage for generating a second signal based on a first signal transmitted from a prior stage circuit; a second gain stage for generating an output signal based on the second signal; multiple candidate capacitors; and a capacitor selection circuit for switching the coupling relationship of the multiple candidate capacitors based on the magnitude of an input signal of the prior stage circuit, so that only a portion of the multiple candidate capacitors could be coupled to the second gain stage at a time.

Abstract: A pipelined analog-to-digital converter includes: a first switched capacitor network, a first digital-to-analog converter, a second switched capacitor network, a second digital-to-analog converter, and an operational amplifier. The outputs from the first switched capacitor network and the first digital-to-analog converter form a first subtraction signal. The outputs from the second switched capacitor network and the second digital-to-analog converter form a second subtraction signal. The operational amplifier is arranged to operably generate an output signal based on the first subtraction signal or the second subtraction signal, and to operably switch coupling relationship of multiple candidate capacitors of the operational amplifier based on the magnitude of an input signal of a prior stage circuit, so that only a portion of the multiple candidate capacitors could be participated in the generation of the output signal at a time.

Abstract: An analog to digital conversion apparatus that includes an analog to digital converter (ADC), a linearity calculating module and a calibration module is provided. The ADC includes a capacitor array, a comparator and a control circuit. The capacitor array receives an input signal to perform a capacitor-switching to generate a capacitor array output signal. The comparator compares the capacitor array output signal and a comparing signal to generate a digital code output result. The control circuit controls the capacitor-switching according to the digital code output result. The linearity calculating module generates a linearity related parameter according to the digital code output result. The calibration module generates a weighting parameter according to the linearity related parameter when the linearity related parameter is not within a predetermined range to adjust the digital code output result based on the weighting parameter to generate an adjusted digital code output result.

Abstract: An amplifier includes an output stage circuit and a compensation circuit. The output stage circuit includes a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The compensation circuit includes a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor. The first capacitor is coupled between the first input terminal and the second output terminal, and is configured to operate as a first Miller capacitor. The second capacitor is coupled between the second input terminal and the first output terminal, and is configured to operate as a second Miller capacitor. The third capacitor and the fourth capacitor are configured to alternately operate as the first Miller capacitor and the second Miller capacitor according to at least one clock signal.

Abstract: A data converter and an impedance matching control method are provided. The data converter includes a comparator, a capacitor array as well as a switch and impedance matching circuit. The comparator includes a first input terminal and a second input terminal. The capacitor array includes a plurality of capacitors, and a first end of each capacitor is coupled to the first input terminal or the second input terminal. The switch and impedance matching circuit is coupled to a second end of a target capacitor among the capacitors and configured to couple the second end to a first reference voltage or a second reference voltage according to a control signal and adjust an impedance according to an impedance adjusting signal, in which the impedance is the impedance of the switch and impedance matching circuit. The first reference voltage is different from the second reference voltage.

Abstract: Disclosed is a correcting device of successive approximation analog-to-digital conversion. The correcting device includes a successive approximation register analog-to-digital converter (SAR ADC) and a digital circuit. The SAR ADC is configured to generate a digital output. The digital circuit is configured to determine whether the digital output conforms to a metastable output, and correct the digital output when the digital output conforms to the metastable output. The metastable output is related with a metastable binary comparison-results sequence including successive K comparison results such as 110000 or 001111. The K comparison results include a first comparison result, a second comparison result and successive M comparison results in turn. The first comparison result and the second comparison result are the same; the M comparison results are the same; each of the first comparison result and the second comparison result is different from any of the M comparison results.

Abstract: A sigma delta modulator includes an integrator, a quantizer, a randomization circuit, and a digital to analog converter circuit. The integrator is configured to integrate an analog signal, in order to generate a first signal, in which the analog signal is a sum of an input signal and a second signal. The quantizer is coupled to the integrator and configured to quantize the first signal to generate a digital signal which has a plurality of bits. The randomization circuit is coupled to the quantizer, and is configured to randomize partial bits in the plurality of bits of the digital signal, in order to generate first control signals. The digital to analog converter (DAC) circuit is coupled to the quantizer and the randomization circuit, and is configured to generate the second signal according to the first control signals and remaining bits in the plurality of bits of the digital signal.

Abstract: The present invention discloses a capacitor layout of a digital-to-analog conversion integrated circuit (DAC IC), comprising a first capacitor group, a second capacitor group and a third capacitor group. The first capacitor group, located within an interior layout area of the capacitor layout, determines a most significant bit (MSB) of the DAC IC and includes a plurality of capacitor units coupled between a first upper circuit and a first lower circuit. The second capacitor group, located within the interior layout area, determines a non-MSB bit of the DAC IC and includes at least one capacitor unit(s) coupled between a second upper circuit and a second lower circuit. The third capacitor group includes a plurality of capacitor units coupled between a third upper circuit and a third lower circuit which are not short-circuited; the capacitor units of the third capacitor group are disposed around the interior layout area.

Abstract: This disclosure provides a charging-steering amplifier circuit and the control method thereof. The charging-steering amplifier circuit includes a charging-steering differential amplifier and a sample and hold circuit. The charging-steering amplifier circuit operates in a reset phase or in an amplifying phase to amplify a differential input signal. The control method includes steps of: in the reset phase, obtaining a common mode voltage of the differential input signal according to the differential input signal; in the reset phase, providing the common mode voltage to one of the charging-steering differential amplifier and the sample and hold circuit; in the reset phase, sampling the differential input signal by the sample and hold circuit to generate a voltage signal; and in the amplifying phase, inputting the voltage signal to the charging-steering differential amplifier.

Abstract: A pipelined analog-to-digital converter (ADC) and an operating method are provided. The pipelined ADC includes a multiplying digital-to-analog converter (MDAC) and a sub-ADC. The MDAC alternatively operates in an amplifying phase and a sampling phase according to two non-overlapping clocks, and performs operations on an input signal in the amplifying phase according to a target voltage determined by a digital code. The sub ADC includes multiple comparators, a determination circuit, and an encoding circuit. The comparators generate multiple comparison results by comparing the input signal with multiple predetermined voltages. The determination circuit generates multiple comparison completion signals in a non-overlapping interval of the two clocks according to the comparison results. The comparison completion signals respectively indicate whether the comparators complete the comparison. The encoding circuit determines the digital code according to the comparison results and the comparison completion signals.

Abstract: A pipelined analog-to-digital converter (ADC) and an operating method are provided. The pipelined ADC includes a multiplying digital-to-analog converter (MDAC) and a sub-ADC. The MDAC alternatively operates in an amplifying phase and a sampling phase according to two non-overlapping clocks, and performs operations on an input signal in the amplifying phase according to a target voltage determined by a digital code. The sub-ADC includes multiple comparators, a determination circuit, and an encoding circuit. The comparators generate multiple comparison results by comparing the input signal with multiple predetermined voltages. The determination circuit generates multiple comparison completion signals in a non-overlapping interval of the two clocks according to the comparison results. The comparison completion signals respectively indicate whether the comparators complete the comparison. The encoding circuit determines the digital code according to the comparison results and the comparison completion signals.

Abstract: This disclosure provides a charging-steering amplifier circuit and the control method thereof. The charging-steering amplifier circuit includes a charging-steering differential amplifier and a sample and hold circuit. The charging-steering amplifier circuit operates in a reset phase or in an amplifying phase to amplify a differential input signal. The control method includes steps of: in the reset phase, obtaining a common mode voltage of the differential input signal according to the differential input signal; in the reset phase, providing the common mode voltage to one of the charging-steering differential amplifier and the sample and hold circuit; in the reset phase, sampling the differential input signal by the sample and hold circuit to generate a voltage signal; and in the amplifying phase, inputting the voltage signal to the charging-steering differential amplifier.

Abstract: The present invention discloses a voltage reference buffer circuit. An embodiment of the voltage reference buffer circuit includes: a first bias generator configured to generate a first bias voltage; a second bias generator configured to generate a second bias voltage different from the first bias voltage; a first driving component coupled to a high voltage terminal, the first bias generator and a reference voltage output terminal, and configured to control a reference voltage at the reference voltage output terminal according to the first bias voltage; and a second driving component coupled to the reference voltage output terminal, the second bias generator and a low voltage terminal, and configured to control a current between the reference voltage output terminal and the second driving component according to the second bias voltage.