Calibration algorithm applied to time-interleaved analog-to-digital converter

Abstract

The invention provides a calibration algorithm applied to a time-interleaved analog-to-digital converter, comprising the following steps: sampling analog signals through multiple sub analog-to-digital converters ADC; processing digital signals obtained after sampling through a field-programmable gate array (FPGA for short), and calculating error values; carrying out real-time feedback regulation according to the calculated error values; and repeating the steps until the error values converge to fixed values. Statistical analysis and feedback regulation are used in the algorithm. Sampling data is processed by the FPGA in real time to get three error values (offset mismatch error, gain mismatch errors and sampling time interval mismatch error), then, real-time feedback regulation is carried out in real time according to the error values until the error values converge, and finally, calibration of the time-interleaved ADC is finished. Therefore, the complexity of the calibration algorithm is reduced effectively, real-time calibration is realized, and hardware resource depletion is reduced.

Description

technical field [0001] The invention relates to the technical field of integrated circuit data converter chip design, in particular to a calibration algorithm applied to a time-interleaved analog-to-digital converter. Background technique [0002] The basic structure of Time-interleaved Analog-to-Digital Converter (TI-ADC for short) is as follows: figure 1 As shown in the middle part, it combines multiple sub-ADCs to achieve uniform and alternate sampling, and doubles the overall sampling rate of the ADC without increasing the sampling rate of the sub-ADCs. However, in an actual circuit, there may be a mismatch in the performance of each sub-ADC, and there may be a time deviation in sampling, resulting in serious mismatch errors, which will seriously affect the overall performance index of the time-interleaved ADC. In order to reduce the impact of mismatch errors on time-interleaved ADC, calibration technology is introduced. Generally, calibration technology is divided into...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a calibration algorithm applied to time-interleaved analog-to-digital converters to solve the problems of high logic resource consumption and poor calibration effect of off-chip calibration algorithms in the prior art

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