How to suppress switching noise in industrial servo drive resistors?

The servo drive resistor (gate series resistor Rg) is the simplest and most effective component for suppressing switching noise (voltage overshoot, ringing). Selection and application by Etymotic: The Rg value needs to balance switching speed and noise; typically, 5-20Ω is chosen for IGBTs and 2-10Ω for SiC MOSFETs. The resistor type should be low inductance (such as thin-film resistors or metal oxide resistors), with parasitic inductance <5nH. The mounting position must be close to the IGBT gate pin, with a trace length <1cm.

To optimize turn-off performance, asymmetrical drive can be used: connect a fast recovery diode (such as FR107) in parallel with Rg, making the turn-off resistance greater than the turn-on resistance. Simultaneously, connect a Zener diode (such as 12V) or TVS (such as ESD5V0D3B) in parallel between the gate and source to prevent gate overvoltage. By adjusting Rg, the ringing amplitude of the switching waveform can be reduced from 30% to below 10%, correspondingly reducing conducted interference related to the switching frequency (such as at twice the carrier frequency) by 6-8dB, with controllable impact on switching losses.