Fairchild IGBTs OK?
Fairchild IGBTs OK?
(OP)
Basically just looking for feedback here on the quality level and how far said IGBTs deviate from the datasheet specs (ie - says it will handle 60A at Tc = 100C but lets out the magic smoke at 40A, etc...). I'm mainly interested in non-punch-through (NPT) or "field stop" IGBTs for easy paralleling and several Fairchild parts keep coming up in my searches at, eg, half the cost of IXYS/Infineon/IRF/etc and since I totally believe TANSTAAFL I'm wondering what gives. So, any feedback would be most welcome. (this will be my first use of IGBTs for something besides tinkering, btw).
-Jeff
-Jeff





RE: Fairchild IGBTs OK?
RE: Fairchild IGBTs OK?
Ic = 40A @ 100C (I never bother with the 25C rating)
Vce[sat] = 1.8V @ 40A
Qg = 120nC @ 400V
*positive TC of Vce[sat] at all current levels shown*
Nobody else has a device with similar specs for less than twice this price; actually the specs are less compelling and the price is usually 3x to 4x higher. I have had good results with Fairchild MOSFETs in the past and have chosen them for the same reasons - they had the best price/performance ratio at the time - but the differences in price were not so stark between their MOSFETs and their competitors' as they are with their IGBTs.
RE: Fairchild IGBTs OK?
Most semiconductor manufactueres are just not intrested in selling a few hundered TO-220 parts.
RE: Fairchild IGBTs OK?
That said, my experience with many semi manufacturers flatly contradicts what you just stated: they are more than happy to provide technical support and design assistance whether I'm buying a 100 parts a year through a distributor, or 10,000 directly from them.
RE: Fairchild IGBTs OK?
$4.52 each vs. $1.79 for the FGH40N60.
The FGH40N60UFD has slightly better gate charge, better Qrr of the diode, and turn-off loss (in mJ/A), and the total switching loss of the IRGP' is 68% of the FGH'.
MMMM, I haven't answered your question about what can be wrong with this part. Looks like a really good price!
RE: Fairchild IGBTs OK?
RE: Fairchild IGBTs OK?
If you can deal with this, even when paralleling, it's fine.
Check Infineon for parts with even lower losses:
ht
Don't know about cost.
Check for conference papers from Infineon on IGBT3 for details of the technology.
Regarding your experience with support: where are you located ?
RE: Fairchild IGBTs OK?
RE: Fairchild IGBTs OK?
I'm in the US - Florida. Until very recently I have never had a poor technical support experience with any US manufacturer; the recent offender was International Rectifier (and I suspect their being taken over by Vishay has a lot to do with that).
sreid - Thanks much for your observations - that's just the sort of second-hand, totally unsubstantiated data I needed to convince me to buy a hundred of those babies ;)
RE: Fairchild IGBTs OK?
RE: Fairchild IGBTs OK?
RE: Fairchild IGBTs OK?
RE: Fairchild IGBTs OK?
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fairchild IGBTs OK?
Oh, and electricuwe - Semikron uses Infineon dice to make the modules, so I went ahead and made the trade-off of higher Qg for lower conduction loss (Qg = 4400nC; gonna take 15A current pulses to transition the gate in 200nS...)
RE: Fairchild IGBTs OK?
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fairchild IGBTs OK?
RE: Fairchild IGBTs OK?
ht
Regarding current rating:
The manufacturer need a number to print on the package, but for a design you need to do a loss calculation according the specific operating conditions. When comparing just by the nominal rating be aware that some rate at 25°C and others at 80°C..100°C case temperature.
Please consider that with IGBTs you do not have the same loss vs. die size trade off as with Mosfets (due to threshold in forward voltage like a diode). So using 600 A rating instead of 40 A will have only a small benefit in losses.
Make a sound choice technically with two or three alternatives and then care about availability and price.
RE: Fairchild IGBTs OK?
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fairchild IGBTs OK?
Looks like the child doesn't play fair.
PS: Nothing against Fairchild, as I've used other components from them with positive results for years.
RE: Fairchild IGBTs OK?
Ic = 40A @ 100C (I never bother with the 25C rating)
The rest of your post assumes such a level of cluelessness on my part it is hard to interpret it as anything but rude. Suffice it to say, I did not choose a 600A module over a 40A single IGBT "just to get the loss down"; I choose the 600A module because it will need to switch 200-300A continuously with peaks approaching 600A.
***
itsmoked - the way I look at the price of the module is this: it offers the equivalent ratings of, say, 20 single IGBTs in one convenient package and someone else went to the trouble to make sure they are all thermally coupled and dynamically matched - that's worth a premium, in my opinion, but to get it for a discount is a no-brainer!
RE: Fairchild IGBTs OK?
On your part you could do lot to avoid confusion, if you clearly state what your requirements are. Starting a discussion on 40 A devices and than later changing to 600 A modules without providing background information is quite misleading.
By the way, if you want to compare devices at 100°C case the Semikron Module is a 490 A device. Assuming this your intial design must have involved paralleling more than 10 Discrete devices, which is not an eays task. The pitfalls you can get by wrong arrangement or driving easily override differences in quality you will find at different manufacturers.
But basicly both approaches are viable. Benfetits of the discrete approach are lower device cost, better heatspreading and, if done properly, lower total stray inductance.
Advantages of the module are integrated isolation of the power circuit to the baseplate, avoiding the difficult external paralleling and the lower manufacturing cost for the inverter.
RE: Fairchild IGBTs OK?
RE: Fairchild IGBTs OK?
So, yeah, I was looking at somewhere between 15 and 20 of the 40A (@ 100C) Fairchild IGBTs in parallel for each side of the half bridge. I'm sure some day I'll find a use for the hundred I bought but for this app I think the Semikron module is the best choice.
Now, figuring out the most economical way to get rid of the waste heat without resorting to liquid cooling... I'm seriously considering embedding heat pipes into a standard aluminum extrusion heat sink... perhaps this should be a topic for another thread?
sreid - yeah, that's the nice thing about IGBTs compared to MOSFETs - IGBTs don't have an intrinsic (parasitic) freewheeling diode (FWD) so one has to be added to the package if needed. Thus, it is much easier to dope it properly for whatever optimizations are desired (low Vf, fast Tfr/Trr, etc.). The poor FWD in a MOSFET is pretty much along for the ride. That said, one not so good aspect of the Semikron module is that the Rth of the diode dice is higher than the Rth of the IGBT dice so the FWD ends up at a much higher below a certain duty cycle... The thermal modeling is driving me crazy as a result.
RE: Fairchild IGBTs OK?
For a single 62mm Module, as long a you do not operate it to close to it's limit, you should be able to find a suitable combination of heatsink and fan. However, the module you have choosen is the maximum rating available in that package, so this makes it a tough job.
Take care that the most critical part thermally may be the diode when driving at low speed (low duty cycle for the IGBT, high duty cycle for the diode)
On IGBT and Mosfet-Diodes:
Intrinsic Diodes of Mosfets are really good in the lower voltage classes, but still very poor for the higher voltage ratings. Even the Diode in Mosfets with fast diode is poor compared to a dedicated diode.
On the choice of device itself:
For long time there has not been significant development in Mosfets in the range from 100...300 V. Therefore a 600 V IGBT outperformed a 15 year old Mosfet-Chip design in many cases. But now semiconductor suppliers recognising a new market for such devices increase their development effort for Mosfets in that range. Check what is announced.
RE: Fairchild IGBTs OK?
That said, it is still true that IGBTs achieve a higher current density for a given die size than MOSFETs, or at least that's my understanding of the current state of the art of both devices.
RE: Fairchild IGBTs OK?
http://www.r-theta.com/
RE: Fairchild IGBTs OK?
RE: Fairchild IGBTs OK?
Anyway, I gave you a star for that one - thanks!
And you read my mind concerning the fan. Any particular manufacturer you prefer? I've had mostly good experiences with Comair/Rotron (formerly EG&G, wasn't it?).
electricuwe - You read my mind, too. Might be time for me to make a foil hat...
I'll be using local desat-detection to protect against abnormal events more or less instantly but an AVR microcontroller (optoisolated, of course) will keep an eye on the average current during motoring (buck) and regeneration (boost) modes and not allow them to exceed either pre-programmed absolute limits or user-programmed limits, whichever is lower.
One thing I'm not sure I can get away with but will be trying out soon: placing the gate driver/sensor board right on top of the IGBT module's bus bars. Besides the obvious benefits like minimizing the loop area between driver and gate, I'm going to see if mounting a couple of Allegro's linear Hall Effect Devices on the top side of the PC board directly centered over the relevant bus bars will allow me to monitor the current in them with reasonable accuracy... The app engineer at Allegro thinks it's an interesting idea but was somewhat skeptical about its accuracy/repeatability. Well, that's what prototypes are for :)
RE: Fairchild IGBTs OK?
http://www.mechatronics.com/
Get it customized for you environment.
For general purpose applications (office, Lab), NMB.
http://w
And the Ultimate; Magnetic Bearing Fans.
h