Low-Overhead Self-Healing Methodology for Current Matching in Current-Steering DAC
Low-Overhead Self-Healing Methodology for Current Matching in Current-Steering DAC
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DOI：
10.1109/tcsii.2015.2404222
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发表时间：
2015-02
期刊：
影响因子：
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通讯作者：
Renzhi Liu;L. Pileggi
中科院分区：
文献类型：
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作者：
Renzhi Liu;L. Pileggi
本文介绍了一种用于电流舵型数模转换器(CS-DAC)电流匹配的低开销自愈方法。与调整电流值的传统校准方法不同，统计元素选择(SES)算法通过组合冗余优化了一元电流单元的选择。这种基于SES的自愈方法放宽了对电流源阵列的匹配要求，以一个电流比较器和一个数字控制器的最小开销实现了高静态线性度。此外，这种低开销方法与其他分段CS-DAC设计完全兼容。采用130 nm工艺实现了具有片上自愈控制环路的14位CS-DAC设计，验证了该方法的有效性。原型芯片的核心面积测量为0.9mm2，电流源阵列占用的面积不到0.1mm2。自愈后，在200-MS/S采样率下，对于2 MHz的输入信号，INLmax测量为0.64最低有效位，无杂散动态范围为85dB。
In this brief, a low-overhead self-healing method for current matching in current-steering digital-to-analog converters (CS-DACs) is demonstrated. In contrast to traditional calibration methods that adjust current values, a statistical element selection (SES) algorithm optimizes the selection of unary current cells via combinatorial redundancy. This SES-based self-healing method relaxes the matching requirements for the current source array and achieves high static linearity at a minimum overhead cost of one current comparator and one digital controller. Moreover, this proposed low-overhead method is fully compatible with other segmented CS-DAC designs. A 14-bit CS-DAC design with on-chip self-healing control loop was implemented in 130-nm CMOS technology to demonstrate the proposed approach. The core area of the prototype chip was measured as 0.9 mm2, with less than 0.1 mm2 occupied by the current source array. After self-healing, the INLmax was measured as 0.64 least significant bit and spurious-free dynamic range was 85 dB for a 2-MHz input signal at 200-MS/s sampling rate.