Application of Tunnel Magnetoresistance for PCB Tracks Current Sensing in High-Frequency Power Converters
Application of Tunnel Magnetoresistance for PCB Tracks Current Sensing in High-Frequency Power Converters
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DOI：
10.1109/tim.2023.3289537
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发表时间：
2023
影响因子：
5.6
通讯作者：
Hui Chen;Weicong Lin;Shuai Shao;Xinke Wu;Junming Zhang
中科院分区：
文献类型：
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作者：
Hui Chen;Weicong Lin;Shuai Shao;Xinke Wu;Junming Zhang
在电源转换器中，电流检测对于保护和控制至关重要。隧道磁电阻（TMR）具有灵敏度高、功耗低、体积小、无损伤等优点，被认为是一种很有前途的电流传感器。然而，高频功率转换器中的快速电压换向和集肤效应将在TMR传感器输出中引起电压尖峰和增益变化。提出了一种梳状屏蔽结构，用于减小功率器件快速换相时产生的输出尖峰。在不影响磁场的情况下，设计了最佳的梳状屏蔽参数。本文还确定了受集肤效应影响最小的安装位置，并给出了不同印刷电路板（PCB）走线宽度下TMR最佳安装位置的计算公式。梳形屏蔽和最佳位置确保了在宽开关频率范围内的TMR电流测量精度。通过一个原型系统验证了所提方法的可行性。通过增加梳状屏蔽，TMR输出尖峰从0.17 V降低到0.02 V。在最佳位置的TMR可以无创地测量0-1-MHz的电流，并确保测量幅度波动在5%以内。
In power converters, current sensing is essential for protection and control. Tunnel magnetoresistance (TMR) is considered a promising current sensor for its high sensitivity, low power consumption, small footprint, and noninvasively measurement. However, the fast voltage commutations and skin effect in high-frequency power converters will induce voltage spikes and gain variations in the TMR sensor output. A comb-shaped shield is presented to decrease output spikes generated by fast voltage commutations of power devices. The optimal comb-shaped shield parameters are designed to shield the electric field without affecting the magnetic field. This article also identifies the install location least affected by the skin effect and gives the formula for the optimal mounting position of the TMR for printed circuit board (PCB) tracks of different widths. The comb-shaped shield and the optimal position ensure TMR current measurement accuracy across a wide switching frequency range. A prototype was built to demonstrate the feasibility of the proposed methods. The TMR output spike is decreased from 0.17 to 0.02 V by adding the designed comb-shaped shield. The TMR in the optimal location can noninvasively measure the 0–1-MHz current and ensure the measurement amplitude fluctuation within 5%.