« first day (3242 days earlier)      last day (766 days later) » 

2:15 AM
@W5VO i don't even require it to be 100% above 95% also sufficient for me. any pointers regarding this? I am expecting some reference design,application notes or some technical articles about the IGBT operation in the duty cycle range above 95%
@W5VO i expect some forums specialized for power electronics. Most of the manufacturers of IGBT power modules dont have forum. Infineon having forum but that is not active like TI forum(Many employees of TI members of the forum)
 
 
2 hours later…
4:14 AM
Holy Freaking Cheezus, some chip designers never raise their eyes above their screens.
If a datasheet says it's giving you a "top side view" of BGA assignments, do you expect it means "view from the side with the balls" or "view from the side without balls"?
Because it sure as hell looks like my vendor figured, "the side where we do the lithography and stuff is the top of the wafer, so the top side view is the view from that side" (and it's a CSP, so that ends up being the side with the balls).
Would'a been cool to figure that out before the boards had sat around weeks waiting for the chips to arrive.
 
 
8 hours later…
12:16 PM
So the "top" side is the "ball" side?
 
 
4 hours later…
4:01 PM
@rdtsc Yep
 
4:49 PM
@ScottSeidman Hey Scott, to what extent is gold-plated PCB biocompatible?
I'm trying to figure out how to form an ECG electrode in a tight space. There's a PCB nearby, so naturally, I'm thinking about creating an electrode out of a PCB.
The electrode will be on the skin for about one hour (or less) a day.
 
5:03 PM
Not sure, but a certain percentage of ppl have a fairly moderate nickel allergy. Enig uses nickel.
 
@NickAlexeev Are you talking research, or are you talking FDA-regulated device? If you're talking FDA, it becomes a much bigger deal, but if you're talking research, I'd go with the gold plating, which should be fine, but add "some people may experience irritation, and if so they should stop" language in the RSRB application and the consent form. If it's FDA, I'll try to dig a bit deeper.
You might find ncbi.nlm.nih.gov/pubmed/23008244 interesting (though it may be too late for you)
 
5:48 PM
@yogece At the power levels that you reach with IGBT modules, you're sorta expected to know what you're doing, or have access to people who do. These modules are intended for switching hundreds of volts at hundreds of amps. You don't usually find that kind of equipment just laying around. If you think you know what you're doing, and you're wrong, things explode (from experience).
A lot of the time, when you have really high / really low duty cycles, switching losses and switching time become significant regarding your circuit. At 100% duty cycle, a high-side driver cannot be bootstrapped. Past that, you have a SOA graph for power dissipation, what more do you want?
 
@W5VO thanks for responding
i am looking for some research publications/articles/video regarding the IGBT for near DC operation. For inverters and motor drive design considerations available from IRF(Now Infineon) irf.com/technical-info/appnotes/an-1202.pdf similarly i am looking for DC chopper
I am not asking for the design help. Just looking for some credible resources regarding near DC IGBT working. I know the junction temperature is the limiting factor for the IGBT i have simulated the design in Semikrons is online simulator.
and i couldn't find information regarding correlation of simulation and bench setup
 
6:36 PM
@yogece isn't Ic the continuous collector current rating?
Usually, there would be a pulsed current rating as well.
 
6:57 PM
@C.Lange Yes. But it is limited by pulse width and junction temperature
No pulse current rating isnt available for IGBT module
 
7:17 PM
Yes, limited by pulse width but you're asking about 100% duty cycle, which is continuous.
 
8:02 PM
Close to 100 % above 95% is okay for me.but i am looking for some credible reference.
 
@yogece -- there are two current ratings on your datasheet. Ic and Icrm. One is for continuous current (100% duty cycle == continuous) and the other is for pulsed current where the pulse is whatever they've defined. You can exceed the ratings when you start to pulse and that's what create the larger SOA. That's the reason that Icrm is 600 A and Ic is 300 A.
If you google "IGBT icrm" or "IGBT ic" you get lots of technical documents from infineon.
 
Isn't it?
@C.Lange I am having semikron SKM400GB125D its a half bridge module rated 1200V/400A i understood that but that current maynot be achievable in the ambient temperature of 40 deg celcius
Icrm is 600A
 
8:35 PM
That's correct. Your maximum current is highly temperature dependent. They spec both the current at 25°C and 80°C. Fig. 2 is the Ic vs Tc curve. Looks like at 40°C you can still pull 400 A Ic.
I'd make sure you understand what every line of that datasheet means. To me, all the information is there. The manufacturer may not spell out the SOA but at this level you should be able to find it.
 
8:54 PM
@C.Lange Thanks for your inputs. Let me try in the bench setup. If you have some resources regarding DC operation of IGBT kindly share with me
 
9:21 PM
@yogece Why don't you try explicitly saying what your specific concerns are?
 

« first day (3242 days earlier)      last day (766 days later) »