A 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 LMS iterative algorithm converges to obtain the estimation of the offset error coefficient and the gain mismatch coefficient respectively, and respectively subtracts the output of the channel to be calibrated; the calibration of the sampling time mismatch includes: first calibrating the channel with a phase difference from the reference channel, and calculating The time error of the channel is calculated, and the average value of the calculated cross-correlation function difference is used as the estimated value of the time error, and the input signal is extracted to complete the calibration in the voltage domain; the sampling time mismatch error of the other channels is obtained by using the improved LMS iterative formula , and calculated to compensate to complete the calibration. The invention effectively improves system dynamic indexes such as SNR and SFDR of the TIADC, has lower calculation complexity and hardware overhead, and is 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...

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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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