Dynamic element matching circuit and method applied to digital-to-analog converter

Abstract

The invention relates to a dynamic element matching circuit and method applied to a digital-to-analog converter, the digital-to-analog converter and a digital-to-analog conversion method. The dynamicelement matching circuit is used for encoding N-bit binary codes a(N-1),..., a1 and a0 into thermometer codes through pseudo-random codes P(N-1),..., P1 and P0 and outputting the thermometer codes. The dynamic element matching circuit comprises N stages of decoding units, an ith-level decoding unit comprises 2<i-1> decoders, and i = 1, 2,..., N. Each decoder of the ith-level decoding unit is usedfor randomly switching a first input signal a(i-1) and a second input signal according to the pseudo-random code P(i-1) and then outputting the signals as the second input signal of the next-level decoder, and the decoder of the Nth-level decoding unit outputs a thermometer code. According to the invention, the decoders of all levels are the same in structure, so that the implementation architecture of a conventional DEM is greatly simplified, the conversion rate is improved, and the circuit more suitable for being applied to a high-speed and high-precision DAC.

Description

Technical field [0001] The invention relates to the technical field of integrated circuits, and in particular to a dynamic element matching circuit and method applied to a digital-to-analog converter, as well as a digital-to-analog converter and a digital-to-analog conversion method. Background technique [0002] High-speed and high-precision digital-to-analog converters (DAC) usually use thermometer code or thermometer code binary code segmentation to improve the matching degree of basic constituent units. However, there is a flaw in the thermometer code. The use efficiency of different data bits is not consistent. That is, if there is a matching error in the DAC, the data will be related to the mismatch, thereby reducing the spurious-free dynamic range (SFDR) of the DAC. Generally, dynamic The component matching algorithm averages the distribution of each data bit, eliminates the correlation between data and gradient error, and improves the dynamic characteristics of the DAC. ...

AI Technical Summary

Problems solved by technology

[0008] The technical problem to be solved by the present invention is to provide a dynamic component matching circuit and method applied to a digital-to-analog converter, as well as a digital-to-analog converter and a digital-to-analog Analog-to-analog conversion method in which decoding is performed from low to high bits and switching is performed while decoding

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