Shunt resistor


電流感測電阻(shunt resistor)通常被放在三個相位之一的線路上。這個電壓降落可以通過一個運算放大器(op-amp)放大,然後被傳感器接收並轉換成數字信號。藉此方式,我們可以在驅動器中檢測電機的電流,並在必要時停止或調整電機的運行,從而保護驅動器和電機,延長其壽命。



  • Fliter
  • Offset
  • Amplification

電阻值越大,給定的電壓降越高當前,因此可用的有用信號。 另一方面,功耗分流電阻隨著電阻值的增加而增加,因此電阻值
主要取決於可接受的最大功耗 (PMAX) 是多少成分。



Layout 建議

  • With reference to Figure 3, and for each of the shunt resistors, directly connect R1 andR4 terminals to shunt resistor terminals. Furthermore, these two should go close toeach other from resistor to op amp to minimize the introduction of differential electricalnoise.
  • Keep traces between resistors and op amps far away from high voltage traces (even ifon different PCB layers). This would help avoid capacitive couplings.
  • Try to place operational amplifiers and related components as close as possible toshunt resistors.


Low-side global current sensing
Low-side current sensing in each leg of the current driver
Inline phase current
High-side current sensing

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