IGBT switch off gate problem; 30kHz PMW uC ; single lowside driver; IR2110 driver IGBT FGA25N120AN ?

Thread Starter

Noob_tronic

Joined Aug 16, 2018
2
Hello,

To design an acceptable schematic for an IGBT dedicated for a DiY forge/cooktop applications, with a frequency range between 50kHz to 200kHz is a goal.

The IR2110 driver and the IGBT FGA250N120ANTD should worked together, unless if I mistaken ? IGBT FGA250N120ANTD as the IR2110 driver are designed for frequencies from 20kHz to 1MHz, and should answer to my needs, but maybe I’m wrong ?

IGBT FGA25N120ANTD : http://www.farnell.com/datasheets/1774719.pdf
IR2110 driver : https://www.infineon.com/dgdl/ir2110.pdf?fileId=5546d462533600a4015355c80333167e

Because that looks easiest for the moment, I guess the IR2110 mosfet driver in a single low-side high-voltage configuration should answer to first steps of tests, with a resistor load. The target is to limit short circuit IGBT destructions risks, with a resistor load. For information, I’ve Electrician certifications.

The resistor charge was used for tests at 30kHz to find the good adjustment for that range of frequencies on the gate. With several other IGBT as the “GT50N322A” I had some troubles.

When I passed 5.5V gate tension, the IGBT stay on ON without Off state when the gate stop the 30kHz PMW signal. That the reason why I ask questions on the forum as newbie newcomer. Maybe something wrong in schematics 1 & 2 attached ?

Several questions about schematics and datasheets :
A - To plug a MKP capacitor between Emitter and Collector as the “AV R76 MKP” 100nF is maybe the solution ?
B - How we can control current in the IGBT ? A current limitation on the gate, or, a VGE tension regulation ? How can I regulate the current ; is it possible ?
C - Why the data-sheet specification precises VGE tension range from 3.5V to 7V, the Ic(A) f (VCE) curves allow a VGE between 6V and 10V, and, on an another line of the data-sheet appear VGE=+-20V ? What is the good PMW tension on the gate ? I’m lost...
D - The 1 kΩ gate resistor isn't maybe a good value ; 10 kΩ is maybe better ?

Thank you for your time.

Nicolas

NB : I've also 47N60C3 mosfets which are maybe more indicated in this application, but I prefer to use the IGBT ?
https://www.infineon.com/dgdl/Infineon-SPW47N60C3-DS-v02_06-en.pdf?fileId=db3a304412b407950112b42dff93492f
 

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Thread Starter

Noob_tronic

Joined Aug 16, 2018
2
Hello,

After some searches and web exchanges, I'm allow to summarize my question with a new schematic and oscilloscope measures attached, for a better understanding of my electronic measure problem.

Oscilloscope measures are demonstrated that the signal should be good on the gate. 15 V-PMW-30kHz with a signal which switch off under zero volt. Unless if I mistaken, that should switch off the NPT IGBT FGA25N120ANTD. Because I can’t measure on high voltage the gate state evolution with my USB oscilloscope, I’m disappointed. Indeed, the circuit breaker differential when I plug the USB oscilloscope cutted off a part of the house electrical network.

Why the gate refused to switch off with 30kHz_15V_PMW. That test destroyed the NPT IGBT with a continuous 8A _ 320Vdc power ?

For the moment I destroyed 20 expensives IGBT before to decide to buy NPT IGBT FGA25N120ANTD and IR2110.

For Electronicians, I guess the answer is obvious ; please help me.

Respectfully

Nicolas
 

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Alec_t

Joined Sep 17, 2013
10,355
For a forge/cooktop application you need switch the IGBT only every few mains cycles to control heat (aka burst mode). That would make IGBT destruction much less likely.
 

cmartinez

Joined Jan 17, 2007
6,461
I'd too consider using a Triac instead. It would be much better suited for a non-precision application such as this. Another advantage would be much less noise and emi being produced .
 
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