SAR ADC-based calibration method and SAR ADC system

Abstract

The invention discloses an SAR ADC-based calibration method and an SAR ADC system. The method comprises the following steps: sampling the same input signal twice, and superposing disturbance signals opposite in direction on the same input signals sampled twice to obtain two quantitative results; and subtracting the two quantitative results in a numeric field, and adjusting weight value of each bitcapacitor in a capacitor array through a least mean square (LMS) algorithm to drive error to approach 0. The method is not only fast in calibration speed and high in precision, but also can realize on-chip integration.

Description

technical field [0001] The invention relates to the field of integrated circuit design, in particular to a SAR ADC-based calibration method and a SAR ADC system. Background technique [0002] With the continuous development of integrated circuits, analog-to-digital converters are gradually developing in the direction of high speed, high precision, low power consumption, and small area. In many systems, the accuracy requirements for analog-to-digital converters are generally around 12 to 14 bits. Factors such as errors seriously affect the performance of the analog-to-digital converter. If it is not calibrated, the accuracy of the analog-to-digital converter is generally limited to about 10 bits, which is difficult to meet the application requirements. In practical applications, A / D converters mostly use calibration techniques to correct the impact of various errors on their performance. [0003] Calibration techniques in analog-to-digital converters generally fall into tw...

AI Technical Summary

Problems solved by technology

[0005] However, currently SAR ADCs with high calibration accuracy and fast calibration speed are difficult to integrate on-chip

The on-chip integrated SAR ADC calibrated by LMS algorithm has the following defects: 1. The calibration accuracy is low, which cannot meet the design requirements of high-precision SAR ADC; 2. The calibration speed is slow, which cannot meet the requirements of system-level applications for high-precision SAR ADC. Requirements; 3. The calibration scheme is complex and requires an additional calibration module, which makes the entire SAR ADC have a large area, high power consumption, long design cycle, and high chip cost

[0006] For the SAR ADC calibrated by the LMS algorithm in the related art, either the calibration speed is slow, the accuracy is not high, the scheme is complicated, or the technical problems cannot be integrated on the chip, and no effective solution has been proposed so far.

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