A built-in self-test technique for load inductance and lossless current sensing of DC-DC converters
A built-in self-test technique for load inductance and lossless current sensing of DC-DC converters
复制标题
用于 DC-DC 转换器负载电感和无损电流检测的内置自测试技术
DOI：
10.1109/vts.2014.6818750
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
B. Bakkaloglu
中科院分区：
文献类型：
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作者：
Tao Liu;Chao Fu;S. Ozev;B. Bakkaloglu
在最先进的电源管理集成电路(PMIC)中使用的集成DC-DC转换器的主要问题之一是动态性能和稳定性因片外元件和输出电流的变化而降低。提出一种测量DC-DC转换器负载电感和直流电阻的高精度内建自测试(BIST)结构。电感的DCR测量还支持对电感上的DC-DC转换器进行连续、无损的平均负载电流检测。内建自测试电路和主信号链均采用低模拟复杂度的频域ΔΣ模数转换器。ΔΣ模数转换抽取滤波器零位还提供电流纹波抵消和平均电流提取。该内建自测试模块可以测量3.6μH到22.3μH范围内的滤波电感值，平均误差为2.0%；电感DCR13MΩ到68MΩ范围内的平均误差为2.1%。通过BIST技术实现的平均电流检测实现了电流测量精度，对于0.1a-1a范围的负载电流，平均误差为2.3%。BIST和电流传感模块占芯片总面积的比例不到6%。该内建自测试电路的输入电压为12V，输出范围为1V-11.5V，适用于3W输出功率的数字DC-DC转换器。
One of the major problems associated with integrated DC-DC converters used in state of the art Power Management ICs (PMICs) is dynamic performance and stability degradation due to off-chip component and output current variations. A high accuracy built-in self-test (BIST) architecture measuring load inductance and DC resistance (DCR) of DC-DC converters is presented. The DCR measurement of the inductor also enables continuous, lossless average load current sensing of the DC-DC converter across the inductor. Both the BIST circuit and the primary signal chain utilize low analog complexity frequency-domain ΔΣADC. The ΔΣADC decimation filter nulls also provide current ripple cancellation and average current extraction. The BIST module can measure filter inductance values ranging from 3.6μH to 22.3μH range with average 2.0% error and inductor DCR 13mΩto 68mΩ range with average 2.1% error. The average current sensing enabled by the BIST technique achieves current measurement accuracy with average 2.3% error for 0.1A-1A range load current. BIST and current sensing modules occupy less than 6% of total chip area. The BIST circuitry is fabricated and tested with a 12V input, 1V-11.5V output range, for a 3W output power digital DC-DC converter.