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What is Miller Clamp output in gate driver?

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I was going through datasheet of Texas Instrument ISO5852 Gate driver IC, But I could not understad what is the functionality of Miller Clamp output pin Shown as pin 7 in
below figure:
miller clamp.PNG
Please someone help me understand this.
 

ronsimpson

Well-Known Member
Most Helpful Member
It's detailed in section 9.3 of the data sheet:
9.3.1 Supply and Active Miller Clamp
The ISO5852S supports both bipolar and unipolar power supply with active Miller clamp.
For operation with bipolar supplies, the IGBT is turned off with a negative voltage on its gate with respect to its
emitter. This prevents the IGBT from unintentionally turning on because of current induced from its collector to its
gate due to Miller effect. In this condition it is not necessary to connect CLAMP output of the gate driver to the
IGBT gate, but connecting CLAMP output of the gate driver to the IGBT gate is also not an issue. Typical values
of VCC2 and VEE2 for bipolar operation are 15-V and -8-V with respect to GND2.
For operation with unipolar supply, typically, VCC2 is connected to 15-V with respect to GND2, and VEE2 is
connected to GND2. In this use case, the IGBT can turn on due to additional charge from IGBT Miller
capacitance caused by a high voltage slew rate transition on the IGBT collector. To prevent IGBT to turn on, the
CLAMP pin is connected to IGBT gate and Miller current is sinked through a low impedance CLAMP transistor.
Miller CLAMP is designed for Miller current up to 2-A. When the IGBT is turned-off and the gate voltage
transitions below 2-V the CLAMP current output is activated.
 
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