When we are enabling PWM , we are observing switching noise on PWM signals as shown in capture. While IGBT on transition (VCE – 192V ->0)/ IGBT off transition(VCE-0V -> 192V) , we are observed this switching noise. (6 gate drivers are used for driving the IGBT module (6 IGBTs)). Can any one suggest how can I decrease this switching noise ?

 

If a heavy current surge/change as the IGBT switches is affecting the PWM supply, that might be getting through to the PWM drive signals. Do the gate driver and IGBT supplies share any common trace, or do you have a star-ground setup?

 

Do all the switching elements have their power decoupled with capacitors to ground?
How long are the leads to the load?

 

If a heavy current surge/change as the IGBT switches is affecting the PWM supply, that might be getting through to the PWM drive signals. Do the gate driver and IGBT supplies share any common trace, or do you have a star-ground setup?

Hi ....Thank you for your support. We are having separate grounds for HV side of Gate driver + IGBT and LV side of Gate driver. Also each gate drivers are having separate isolation.