Current steering type digital-to-analog converter for achieving digitization calibration, chip and communication terminal

Abstract

The invention discloses a current steering type digital-to-analog converter for achieving digitization calibration. The current steering type digital-to-analog converter separately compares a receivedcurrent output bit-by-bit by a thermometer coding module with the sum of currents output by a binary coding module and a reference power source circuit via a current subtractor circuit; a comparisonresult is transmitted to a control and calibration logic circuit via a comparator; the control and calibration logic circuit controls the magnitude of a calibration current output by a corresponding calibration current source until the output of the comparator turns over, and thus the calibration process of the current output bit-by-bit by the thermometer coding module is completed. According to the current steering type digital-to-analog converter, the differential nonlinearity of the piecewise hybrid coded current steering type digital-to-analog converter can be reduced, and the linearity ofthe current steering type digital-to-analog converter can be improved under the premise of not increasing too much chip area, power consumption and size of the unit current source.

Description

technical field [0001] The present invention relates to a current-steering digital-to-analog converter, in particular to a current-steering digital-to-analog converter that realizes digital calibration, and also to an integrated circuit chip including the current-steering digital-to-analog converter and a corresponding communication terminal , belongs to the technical field of analog integrated circuits. Background technique [0002] The digital-to-analog converter is a bridge connecting digital signals and analog signals, and is widely used in digital-analog mixed-signal systems. Usually, a current-steering digital-to-analog converter is used to convert digital signals to analog signals. Due to the high degree of current matching, the current steering digital-to-analog converter can achieve high conversion accuracy. [0003] like figure 1 As shown, the existing current-steering digital-to-analog converter is mainly composed of several current sources and several current ...

AI Technical Summary

Problems solved by technology

Therefore, in the prior art, after selecting a fixed value of p, in order to reduce the differential nonlinearity of the current steering digital-analog converter in the form of segmented hybrid coding, it can only be realized by simply reducing the mismatch level of the unit current source, but this will inevitably lead to Increased power consumption and area consumption

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