Enhanced <i>di/dt</i>-RC Sensing Structure for Accurate Dynamic Current Measurement in Paralleled SiC MOSFETs

Paralleling SiC <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small>s offers a cost-effective way to increase current capability for high-power applications. However, unbalanced dynamic current sharing among paralleled devices can result in uneven losses and thermal distribution, potentially causing device failure. To monitor or actively balance the currents, a current sensor capable of tracking high-<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">di/dt</i> dynamic currents is required. Existing sensing methods, however, often struggle with poor integration and high cost, while the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">di/dt</i>-<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RC</i> sensing for paralleled devices remains underexplored. This article presents a comprehensive evaluation of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">di/dt</i>-<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RC</i> sensing for paralleled SiC <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small>s. To enhance the sensing accuracy and mitigate issues generated by circulating current, a novel <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$R_{\mathrm{K}}$</tex-math></inline-formula> sensing structure is proposed in this article. The proposed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$R_{\mathrm{K}}$</tex-math></inline-formula> sensing structure requires only three passive components (2 resistors and 1 capacitor) per <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> and can be easily scaled for multiple devices, making it highly advantageous for industrial applications. Circuit-level simulations support the analysis, and experimental results validate that the proposed sensing structure can accurately track dynamic currents under various conditions.