IGBT driver gate resistance

[neuling]

Hi there,

I need to drive IGBT for 3 phase inverter. I have never design driver circuit before. I have found couple of application notes however can not calculate gate resistances (on and off). I need to use PS9552.

I will use 18kHz switching frequency. IGBT average current is 4 A and antiparallel diode current is 0.6 A for nominal conditions.

If you suggest something that would be great.

Thanks in advance...

 

[ronv]

Since the driver can supply .5 amps minimum I would use something like 20 ohms.

 

[Ubergeek63]

your best bet is to use the number (probably 5 ohm gate resistance) they use on the spec sheet and make sure you are using IGBTs rated for 20KHz min hard switch frequency.

2 reasons.

1. low speed IGBTs are limited by dissipation.
2. miller capacitance might blow the gate when switching with 20 ohms in the gate.

Dan

 

[duffy]

Yes, watch out for that Miller capacitance effect, also called "gate excursion". This is one I learned in the school of hard knocks. You would think a high value would be fine for the gate on a mosfet or igbt, and... BANG! Whoops.

 

[ronv]

Guess I should have ask what IGBT you are using or planning to use. Yours is small (4amps) so I guess like this one in which case 20 ohms is more than enough. In any case check the data sheet.

https://www.electro-tech-online.com/custompdfs/2012/02/irg4ibc10ud.pdf

 

[neuling]

Thank you so much for your valuable suggestions. I am going to use IKW15N120H3. 15 A 1200 V IGBT. The RMS value of the inverter output is 10 A. I also have to use 18 kHz switching frequency.

 

[Ubergeek63]

Thank you so much for your valuable suggestions. I am going to use IKW15N120H3. 15 A 1200 V IGBT. The RMS value of the inverter output is 10 A. I also have to use 18 kHz switching frequency.

you do realize that you have 30W in switching losses alone, dont you? that part will have a 20C rise in temperature from the case to the junction at NO LOAD.

BEWARE SPECMANSHIP!!!

Dan