Current type digital to analog converter

Abstract

The invention relates to the digital to analog conversion circuit technology field, especially relating to a current type digital to analog converter. The current type digital to analog converter comprises two sub digital to analog converters with same structures, same digital input signals and same clock input signals, wherein a positive output terminal of a first sub digital to analog converter is connected with a positive output terminal of a second sub digital to analog converter, a negative output terminal of the first sub digital to analog converter is connected with a negative output terminal of the second sub digital to analog converter, sums of difference currents of the two sub digital to analog converters are combined to form difference output of the current type digital to analog converter. In the invention, output currents of the two sub digital to analog converters are collected together, dual digital random complementation technology is employed, in the condition of not increasing a work speed requirement of the digital to analog converter, a spurious-free dynamic range is raised, by employing a simple structure, improvement of a digital to analog converter dynamic characteristic is realized, a circuit design is easy to realize and a control mode is simple, and the current type digital to analog converter has strong application prospect.

Description

technical field [0001] The invention relates to the technical field of digital-to-analog conversion circuits, in particular to a current-mode digital-to-analog converter. Background technique [0002] With the continuous development of signal processing technology and communication technology, the interface technology between digital signal and analog signal has become the bottleneck restricting the digital-analog hybrid system. In order to meet the high-speed and high-precision data conversion requirements, digital-to-analog converters and analog-to-digital converters need to achieve the highest possible speed and accuracy. In modern high-speed digital-to-analog converters, the current-mode digital-to-analog converter has become the preferred structure of engineers because it can directly drive resistive loads and has a relatively fast speed. [0003] The structure of the common current-mode digital-to-analog converter is as attached figure 1 As shown, it mainly includes ...

AI Technical Summary

Problems solved by technology

DRRZ technology reduces nonlinear distortion to a certain extent and improves SFDR, but there are still some problems. First, the signal energy output by DAC is reduced by half compared with the signal energy output by traditional DAC; secondly, the zeroing of DAC And stabilization is completed within half a clock cycle, which makes the DAC work at a higher speed and increases the design difficulty

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