adc adaptive filter digital calibration method

Abstract

The invention discloses an ADC adaptive filtering digital calibration method. The ADC adaptive filtering digital calibration method comprises the steps: data format constraint is set, namely adopted original data are binary numbers, other adopted data are singed complement fixed-point numbers, and initialization values are set for other data; linear calibration operation including linear calibration error value calculation and weight value and disturbance signal value update is performed; gain calibration operation including optimal weight sum calculation, ADC output characteristic curve gain coefficient calculation and end result operation is performed. According to the ADC adaptive filtering digital calibration method, the data format is well set, and shift operation, concatenation operation, fixed-point number addition operation and fixed-point number multiplying operation are adopted in an algorithm to replace floating-point multiplication, so that the algorithm facilitates design achievement of a hardware circuit, and the expenditure for the hardware circuit is reduced. The curve adjustment of an ADC output characteristic curve can be quickly completed and 2-based binary result output can be quickly achieved by means of a gain calibration algorithm adopted in the ADC adaptive filtering digital calibration method, the accuracy of an ADC can be greatly improved, and the usage range of the ADC can be greatly widened.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to an ADC adaptive filtering digital calibration method. Background technique [0002] The main error sources of ADC include comparator offset (Offset), capacitance mismatch (Mismatch), gain error (Gain error), etc. Among them, the DAC capacitance mismatch caused by manufacturing is impossible to avoid, and the ADC caused by it The nonlinear change of the output characteristic curve has the greatest impact on the performance of the ADC. The traditional analog improvement method is to use a large capacitor unit, but it brings area and power consumption overhead. Or use a small capacitor array instead of a large capacitor array to improve the linearity of the ADC, but this method will increase the difficulty of control and reduce the speed of the ADC. The digital calibration method using adaptive filtering algorithm is becoming the mainstream technology ...

AI Technical Summary

Problems solved by technology

The existing adaptive filtering algorithm realizes linear calibration, and the digital circuit requires a large-scale computing unit, which is complicated to realize

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