IGBT driver update: I called International Rectifier

I decided to just call IR on the phone. Asked them for a 1,200V gate driver for large IGBTs, with negative reverse bias. Spoke to a very knowledgeable and helpful engineer.

He suggested a new chip IR22141SS. This chip has negative reverse bias, can drive large IGBTs, has 1,200 V isolation, needs only one supply voltage, etc etc etc. He also suggested to read design tip DT04-4. I printed the datasheets and the DT, and so far, everything looks like this chip perfectly suits my needs, except that it is in SSOP and I have a DIP breadboard.

I think that there are adapters that cam change SSOP24 into DIP.

AK24D300-SSOP.8mm 24 Pin SSOP 0.8mm PITCH to DIP

If you think a schematic contains all the relevant information, you will find you are sadly mistaken. (Inductance is one key.)

And the best part is...

I called their dealer on the phone, and then they called me back. They were able to order me free samples of these chips (2 chips). The rep, a super nice woman, said that I should have them on Friday or on Monday.

Be careful with them !

When the IGBTs fry - the driver normally goes too .

Graham

I will try to be careful indeed. I will make a detailed drawing of the relevant part (minus signal generator part) and will post it prior to powering it up.

Forgot to say. There would not be much to that schematic. The chip has almost everything, it just needs a diode, bootstrap capacitor and possibly a few resistors.

You are right. I will try to actually measure inductance of my welder. I think that I can do it with the stuff that I have (decade resistor, signal generator and voltmeter).

Speaking of IGBTs, I'm thinking about something like this:

I was also thinking of a cooked-up circuit something like

Any comments?

Tim

-- Deep Fryer: a very philosophical monk. Website:

You are right, DT04-4 discusses layont of the circuit.

I suspect that Win was trying to alert you to layout issues wrt the gate driver actually. Read IR's app notes thoroughly !

Graham

I had a funny experience in the early '60's while working on alternator regulator designs.

The control chip sat on the ground tab of the package leadframe. Field current, ~5A PWM'd, flowed under the chip. At every switch of state all hell broke loose. Turned out that the resulting magnetic field moved the BJT base current sideways killing the beta.

Redesigned the leadframe to have the control chip on its own no-current-under stub cured the problem.

...Jim Thompson

There's a weldor about 5 or 6 feet from my office, welding 1/2" or so mild steel. I don't know what amps setting he's using, but every time he strikes an arc, my monitor distorts from the magnetic field. I don't know how much inductance that translates to, but it's almost scary, thinking about how to deal with that kind of current/volts/transients with semiconductors. And it's not power line droop - the image actually twists! =:-O

Good Luck! Rich

robert

I have a small desk fan sitting on my desk, 1.5 ft away from my screen. It uses 0.55 amperes of 110V. I need it on cold days because I am sitting right under an air conditioning opening blowing hot air.

Whenever I turn that fan on, the image on my screen begins to shake.

The reason for relaying this is that I am not sure just how many conclusions we can make from seeing image distortion.

That said, I want to thank you and another poster for making me aware of high inductance of the welder and I will try to perhaps delay turn off enough to see some cross conduction.

I read in sci.electronics.design that Ignoramus24489 wrote (in ) about 'IGBT driver update: I called International Rectifier', on Wed, 12 Oct 2005:

Depends how much it shakes, but think around 3 A/m or 3.6 uT.

i know that one, had little hot balls falling out of 690+ series today! bye bye IGBT's

Yes, worst case, I will learn something. I do not have the time to go through an entire tube of stuff, blowing them up. If it does not work on the first and second time, I will just give up.

driver

That's what I was, in fact, planning on doing. :-(

Is there some proto board type thing that is acceptable?

driver

Thanks. I am reading about it now. If I have to do it, I have to do it.