A segmented current steering digital-to-analog converter circuit and a calibration method

Abstract

The invention discloses a segmented current-steering digital-to-analog converter circuit and a calibration method. The current-steering digital-to-analog converter circuit comprises a current source array, a current source switch array, an encoding circuit, a serial-to-parallel conversion circuit, a latch circuit and a calibration circuit. The circuit is integrated into the circuit; on-chip calibration realized, meanwhile, the defect that a binary current source in the sectional type current steering digital-to-analog converter cannot be calibrated by a traditional calibration circuit is overcome; the current source of each bit in the segmented current steering digital-to-analog converter is calibrated in sequence, so that the matching degree between the current sources is improved, and the static linearity, the spurious-free dynamic range and other performances of the digital-to-analog converter are improved.

Description

technical field [0001] The invention relates to the technical field of digital-analog hybrid integrated circuits, in particular to a segmented current steering digital-to-analog converter circuit and a calibration method. Background technique [0002] In the current steering digital-to-analog converter, a segmented structure is generally adopted, and the high bit uses a thermometer code, and the current output capability of the corresponding main current source array is exactly the same; the low bit uses binary coding, and the current output capability of the corresponding main current source array is binary. relation. The input data is input to the encoding circuit, wherein the high data bit segment is encoded according to the thermometer, and the low data bit segment is encoded according to the binary system. The encoded data is input to the current source switch array after being synchronously latched by the parallel-to-serial conversion circuit and the latch circuit. By...

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Problems solved by technology

The patent only describes the circuit structure used for calibration and the connection method between the calibration module and the normal module, but does not disclose the specific calibration algorithm, so it is impossible to evaluate the specific accuracy that calibration can achieve

[0007] For another example, the patent application number CN201510060526 discloses a current source calibration method. In this patent, although each current source of the segmented current steering digital-to-analog converter can be calibrated, the actual implementation of the circuit , using an off-chip circuit, the calibration accuracy will decrease with the change of the external environment, and it is difficult to meet the accuracy requirements

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