TIADC system calibration method based on digital-analog mixed signal

Abstract

The invention discloses a TIADC system calibration method based on a digital-analog mixed signal. The method comprises a step of calibrating inter-channel imbalance and gain mismatch, wherein the calibration comprises respectively obtaining to-be-calibrated channel output and reference channel output for the imbalance and the gain mismatch, performing convergence by using an LMS iteration algorithm to obtain estimation on each of an imbalance error coefficient and a gain mismatch coefficient, and respectively subtracting the imbalance error coefficient and the gain mismatch coefficient on theto-be-calibrated channel output to obtain the output of the to-be-calibrated channel; a step of calibrating the sampling moment mismatch, wherein the calibration comprises firstly calibrating a channel with phase difference from the reference channel, computing the channel time error, and taking a computed mean value of the cross-correlation function difference as a time error estimation value, and extracting an input signal to accomplish the calibration at a voltage domain; obtaining the sampling moment mismatch error of other channels by using the improved LMS iterative formula, and computing to perform compensation, thereby accomplishing the calibration. Through the calibration method disclosed by the invention, the SNR, the SFDR and like system dynamic indexes of the TIADC are effectively improved, and the method is low in computing complexity and hardware expenditure, and easy to integrate.

Description

technical field [0001] The invention relates to a TIADC system calibration method based on a digital-analog mixed signal, and belongs to the technical field of high-speed analog-to-digital converters. Background technique [0002] With the rapid development of the integrated circuit industry, digital signal processing technology is widely used in various fields such as communication, medical treatment, and consumer electronics because of its advantages such as high speed, high precision, low cost, and anti-interference. However, the vast majority of physical quantities in the real world, such as sound, image, light, electricity, temperature, and pressure, are analog signals, and can only be used through ADC (Analog-to-Digital Converter), an important bridge connecting the analog world and the digital world. in digital signal processing. Today, the demand for high-speed, high-precision, and low-power ADCs is increasing in the fields of wireless communication, radar, measurem...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, to provide a TIADC system calibration method based on digital-analog mixed signals, to overcome the influence caused by various errors in the TIADC system, and to achieve a low computational complexity and low hardware From the perspective of overhead, the digital-analog hybrid technology based on digital calibration is adopted. While obtaining good anti-PVT capability, it cancels the need for complex FIR filter banks for full digital domain calibration, and estimates and calibrates various errors in the TIADC system.

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