Demystifying and Mitigating Code-Dependent Switching Distortions in Current-Steering DACs

被引：30

作者：

Lai, Longqiang ^{[1
]}

Li, Xueqing ^{[1
]}

Fu, Yushen ^{[1
]}

Liu, Yongpan ^{[1
]}

Yang, Huazhong ^{[1
]}

机构：

[1] Tsinghua Univ, Dept Elect Engn, Beijing 100084, Peoples R China

来源：

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS | 2019年 / 66卷 / 01期

基金：

美国国家科学基金会;

关键词：

Current-steering; digital-to-analog converter (DAC); dynamic element matching (DEM); element transition rate; intermodulation; switching distortion; D/A CONVERTER; DYNAMIC SFDR; CMOS DAC; GS/S; IMPROVEMENT; BANDWIDTH; IMD; GHZ;

D O I：

10.1109/TCSI.2018.2866819

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

This paper analyzes the intermodulation between the element transition rate and the output-dependent unit switching distortion, i.e., the switching distortion of one switching unit, in current-steering digital-to-analog converters (DACs). The analysis and experimental results reveal how this intermodulation affects the DAC linearity. Based on this, we also propose a technique, termed random pairwise swapping (RPS) to improve the linearity of dynamic-element-matching-decoded DACs. Compared with existing techniques, RPS needs no half-cycle RZ operations and, thus, has no related vulnerabilities. In addition, the RPS could deal with the mismatch between different channels effectively. A 14-bit experimental DAC is fabricated in a 65-nm CMOS process. Measured results at 1.0-GS/s show above 72-dBc SFDR within 422-MHz bandwidth and 8-10-dB image tone suppression by the proposed RPS technique. At 3.0 GS/s, the SFDR is over 60 dBc within 600-MHz bandwidth.

引用

页码：68 / 81

页数：14