Calibration method and calibration system

Abstract

The invention relates to a calibration method and a calibration system. The calibration method is suitable for a successive approximation analog-digital converter, and the successive approximation analog-digital converter comprises a capacitor array. The calibration method comprises the following steps: inputting an input signal into the analog-digital converter, wherein the analog-digital converter generates an output signal according to the input signal, and the output signal comprises a plurality of specific digital codes; calculating respective average code densities of a plurality of digital code groups in the plurality of specific digital codes, wherein each digital code group comprises one or more specific digital codes in the plurality of specific digital codes; comparing the average code density of a first target group in the plurality of digital code groups with a first reference code density to generate a first comparison result; and calibrating the capacitance value of a first capacitor unit to be calibrated of the capacitor array according to the first comparison result. The calibration method can be used for calibrating the successive approximation analog-digital converter in real time.

Description

technical field [0001] The disclosed document relates to a calibration method, especially a calibration method for calibrating the output error of a continuous approximation analog-to-digital converter. Background technique [0002] The continuous approximation analog-to-digital converter (successive approximation ADC, referred to as SARADC) has the characteristics of low power consumption and small size, so it is widely used in today's electronic products. The continuous approximation analog-to-digital converter uses a capacitor array to sample and successively approximate the input signal, wherein the capacitance value of each capacitor in the capacitor array needs to be accurately arranged according to the rising power of 2. For example, the capacitance values ​​of the capacitor array of a 4-bit continuous approximation analog-to-digital converter are 8C, 4C, 2C and 1C in sequence. If the capacitance value of the capacitance array of the continuous approximation analog-t...

AI Technical Summary

Problems solved by technology

If the capacitance value of the capacitor array of the continuous approximation analog-to-digital converter has an error due to process factors, it will inevitably lead to an incorrect output result.

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