gate drive circuit

Thread Starter

harpal

Joined May 12, 2008
3
hi

i need to design a high speed gate drive circuit with an optocoupler and IGBT...is there any website or circuit that i can look at to give me an idea on how to design it...thanks in advance
 

ametso

Joined Apr 30, 2008
13
The 6N137 opto isolator probably don't work with IGBTs.
Because the 6N137 is designed for digital isolation (low current+voltage ratings). Instead the IGBTs drives a high power and even they have a "FET" like gate (=high input impedance) driving of them requires quit a lot of energy due to the construction of IGBT.

I check the data sheet of the 6N137 and there found that the absMAX output current is 50mA. So it means that you can't shut down the IGBT very fast (needed some serial resistance between IGBT gate and the opto) keeping gate current under the limit of optos.

Also you propably can't fully open the IGBT due to the absMAX output voltage limit, whitch was as low as 7V.

I recommend that you visit some sites of the IGBT manufacturer and explore their application notes about IGBT driving.

some links for you:
www.pwrx.com
www.ixys.com
www.irf.com
 
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