An active Miller clamp can help add an additional low impedance path to bypass the Miller current and prevent the high dV/dt introduced unintentional turn-on through the Miller capacitance. Different from the internal active Miller clamp, an external active Miller clamp function is used for applications where the gate driver may not be close to the power device or power module due to system layout considerations. An external active Miller clamp function provides a 5-V gate drive signal to turn on the external Miller clamp FET when the gate driver voltage is less than the Miller clamp threshold, V_CLMPTH. Figure 7-7 shows the timing diagram for the external active Miller clamp function.

Figure 7-7 Timing Diagram for External Active Miller Clamp Function