[SOLVED] My IR2112 is burning out

[Mohammad Zubair]

Hi

My inverter Circuit is working very Fine. My IGBTs are producing the required output without getting any heated up or any other problem.

My circuits works just perfect upto a DC Bus Voltage of +220V. When I increase my voltage level beyond +220V, my IR2112 IC gets burned out.

Now, by my understanding IR2112 should be able to handle DC Bus voltage upto +600V.

By the way, I am using PWM frequency of 15 kHz

 

[brushhead]

Just a comment there is no decoupling cap on the supply rails? That could easily set up instability in the chip?

 

[Mohammad Zubair]

What Function does a decouplicg capacitor play
Can you please elaborate a little to me

 

[Orson Cart]

Vdd & Vcc could use a cap to stabilise the supply at these points, the 1N4007 sees the 15kHz and the high volts switching and will die eventually (as it is a very slow diode!), also if your power layout has too much wiring inductance then Vs can go below ground (yes even with the 1N4007 there) and kill the 2110, check with scope on Vs as toy raise the HVDC and see if it goes below ground.
For large IGBT's it is a good idea to buffer the 2110 with emitter followers (npn+pnp).
Instead of the 5408, how about a high speed (50-75nS) 600v 1A diode...
the 33uF bootstrap cap is a bit large, try 4u7.

 

[ravindragudi]

As a standard practice it will be good to use gate discharge diodes across the gate resistors on HO and LO.

For the present issue, my suspicion is on IGBT's gate drive requirement. I am not fully sure, but review the DS for the IGBT particularly for gate drive at the operating voltage and load current where failure is happening. Attached is snap shot of Ic vs Vge for the noted IGBT in your schematic. This may give you clue on where to fix the issue.

 

[Mohammad Zubair]

I have used discharge diodes in my hardware, but I forgot to put it in the schematic.

Ok, problem I was having that IR2112 ourput currents are somewhat low. So, I used IR2113 and everything became normal