TIADC system sampling moment mismatch digital background calibration method with low hardware overhead

Abstract

The invention discloses a TIADC system sampling moment mismatch digital background calibration method with low hardware overhead. On the basis of Lagrange interpolation, a reconstruction filter is realized to compensate the mismatch at the sampling moment. By simplifying the polynomial expression of the interpolation coefficient, compared with other perfect reconstruction methods, the architectureprovided by the invention has the advantages that about 41% of multipliers are saved, and the number of adders is also greatly reduced. Simulation verification is carried out in a four-channel 800MSPS 12-bit TIADC system, and the result shows that the TIADC system can obtain at least 72dB SNDR within the bandwidth of 0.4 fs input signals. Due to the full-digital realization characteristic of thecalibration algorithm, the method is very suitable for being applied to FPGA or DSP equipment to realize data post-processing. Meanwhile, in a high-speed multi-channel TIADC system, the number of multipliers and adders which are greatly reduced is more easily integrated in a chip, and conversion between different advanced process nodes is more flexible.

Description

technical field [0001] The invention relates to the technical field of high-speed analog-to-digital converters, in particular to a low hardware overhead TIADC system sampling time mismatch digital background calibration method. Background technique [0002] High-speed digital forming technology can obtain the most detailed information of useful signals and is widely used in many fields, such as nuclear physics experiments, data communications, test instruments and medical imaging. For high-speed digital shaping technology, time-interleaved ADC (Time-Interleaved ADC, TIADC) is based on the current ADC technology to obtain a higher sampling rate is known. However, the offset, gain, and sampling time mismatch between channels reduce the dynamic performance of the TIADC system such as spurious-free dynamic range (Spurious FreeDynamic Range, SFDR) and signal-to-noise-distortion ratio (Signal-to-Noise and Distortion, SNDR). Therefore, mismatch calibration between channels has alw...

AI Technical Summary

Problems solved by technology

However, these self-adaptive methods have relatively complex calculation conditions, and they need to consume too many hardware resources when implemented with FPGA and DSP hardware. At the same time, the input signal needs to be oversampled and the mismatch calibration of the complete Nyquist band cannot be realized.

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