Successive approximation type analog-to-digital converter and error correction method and device based on double comparators

Abstract

The invention discloses a successive approximation type analog-to-digital converter and an error correction method and device based on double comparators. The successive approximation type analog-to-digital converter comprises a digital-to-analog converter, a first comparator, a second comparator, a successive approximation logic circuit, an error correction logic circuit and a comparator clock generation circuit. The second comparator control clock is delayed for a certain time length compared with the first comparator control clock; The two comparators are connected with the digital-to-analog converter and the successive approximation logic circuit; The first comparator receives and compares positive and negative output end signals before the voltage of the digital-to-analog converter isstable, and outputs a first comparison result to the successive approximation logic circuit; The second comparator receives positive and negative output end signals after the voltage of the digital-to-analog converter is stabilized, compares the signals and outputs a second comparison result to the successive approximation logic circuit; The successive approximation logic circuit performs error correction according to the first comparison result and the second comparison result. The double comparators are arranged, and the first comparator is corrected through the second comparator, so that the conversion accuracy and the conversion rate are improved.

Description

technical field [0001] The invention relates to the technical field of digital-to-analog conversion, in particular to a successive approximation analog-to-digital converter, an error correction method and device based on a double comparator. Background technique [0002] ADC (Analog-to-Digital Converter, analog-to-digital converter) converts analog signals into digital signals. Currently, the ADC includes a DAC (Digital to analog converter, digital-to-analog converter), a comparator, and a successive approximation logic circuit. When the ADC determines the binary code of the current bit, the DAC inputs the positive-phase signal and the negative-phase signal to the comparator, and the comparator compares the positive-phase signal and the negative-phase signal, and transmits the comparison result to the successive approximation logic circuit. The successive approximation logic circuit confirms the binary code of the current bit according to the comparison result. [0003] Ho...

AI Technical Summary

Problems solved by technology

[0003] However, when the control signal of the DAC changes, the input voltage of the comparator will change. If the comparator waits for the voltage on the capacitor array of the DAC to stabilize before starting the comparison of the next bit, the conversion rate of the ADC will be very slow.

If the comparator compares before the DAC voltage stabilizes, although the conversion speed can be improved, the error is large, resulting in poor accuracy of the ADC.

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