controller PCB, work in progress

[Arlo1]

But now that Zombies and I found these http://ca.mouser.com/ProductDetail/IXYS ... bs1A%3d%3d
The 4468 and 4668 dont seem as awesome!

[nieles]

But now that Zombies and I found these http://ca.mouser.com/ProductDetail/IXYS ... bs1A%3d%3d
The 4469 doesnt seem as awesome!

i am curious to know how you come to that decision. it is not fair to compare a 200v fet with a 100v fet.
the only awsome about the ixys fet i can find is the thJC and the thCS

if we compare the IRFP4668 fet with the IXFK230N20T

fet:      IRFP4668     IXFK230N20T

• Vdss:     200v         200v

• Rds(on):  8.0mR        7.5mR   (lower is better)

• Qg:       161nC        378nC   (lower is better)

• price:    5.90         6.27    (20-25 pieces)

to me the irfp4668 looks better

[Teh Stork]

The biggest improvement on the IR fet compared to the IXYS fet is the output capacitance, switching something with 2,5nF output capacitance requires some serious dedication to layout and possibly snubbers. With the 0,8nF the IR present, you don't need these kind of band aids. And sometimes several smaller fets with capabillity to switch faster is better.

[Arlo1]

Why is it not fair to compare fets of different voltages? If you look at the actual watts in the end they are way better. I thought about the ixsy 100v version of what we got but it has the same current limit based on the same leads !

[liveforphysics]

Why is it not fair to compare fets of different voltages? If you look at the actual watts in the end they are way better. I thought about the ixsy 100v version of what we got but it has the same current limit based on the same leads !

In practice after a few dozen test-to-failures of the best lowest Rds-On TO-247 package fets from IXYS and IR, I've never had a leg fail yet before the die inside gets so hot it crackles and lets its smoke out.


This is my current favorite 150v part (at least from a datasheet perspective, I haven't had one in person yet). It's the only SMT fet package that actually is capable of being cooled, and it's got a combined Rth of sub 0.3, which is way better than all the non-isolated tab packages that show a combined Rth of 0.25, but it's not actually what you're going to get because it's not an isolated tab your cooling, and after you stick the thermal pad to electrically insulate it, you've doubled the Rth.

http://ixapps.ixys.com/DataSheet/DS100434A(MMIX1F360N15T2).pdf

Mod edit:Thanks mitch, we used your fix for Luke's link.

[MitchJi]

Hi,

Fixed the link:

This is my current favorite 150v part (at least from a datasheet perspective, I haven't had one in person yet)....

http://ixapps.ixys.com/DataSheet/DS100434A(MMIX1F360N15T2).pdf

[Arlo1]

Yes luke then you have to look at the price!

[The Mighty Volt]

Will these be available to buy and populate by people who don't know anything about electronics per se but can solder?

Cheers.

[Arlo1]

i am curious to know how you come to that decision. it is not fair to compare a 200v fet with a 100v fet.
the only awsome about the ixys fet i can find is the thJC and the thCS

if we compare the IRFP4668 fet with the IXFK230N20T

fet:      IRFP4668     IXFK230N20T

• Vdss:     200v         200v

• Rds(on):  8.0mR        7.5mR   (lower is better)

• Qg:       161nC        378nC   (lower is better)

• price:    5.90         6.27    (20-25 pieces)

to me the irfp4668 looks better

Code: Select all

You have to add three major components to your comparison.
                    4668                 ixfk230n20t
25deg AMP   130                     230
100deg AMP  92                      160 (limited by the leads)
Cooling        .24 degC/W        .15degC/W
Junction/Case .29degC/W     .09degC/W 

Then with the ixys part you look at the Current vs temp chart and you see from 0-125 degC its limited to 160 amps based on the leads.
Also look at the safe operating area Chart 8 in 4468 datasheet and at 100uS on time and 200v you are limited to 1-2 amps (that's not a typo) they don't list a 25 uS pulse
Then look at ixfk230n20t chart safe operating area for 100 uS to be fair and at 200v you are limited to 50 amps!
I plan for <25 uS on times so you can look at 168v and 25uS on time for a safe max of ~400 amps pulsed. (I plan to stay a margin below 160) But with my 6 fet test cuicuit I will be testing to destruction on a couple motors on my big dyno to see how much power 6 fet can make to figure out roughly how many fets I need for my big controller!
BTW we have TO264 packages!

[Lebowski]

I'll post a controller build in the next few days about the 6 FET I constructed with the PCB
described in this thread. Very very cool build if I say so myself Will show you
guys how its done No clue about how much power it can handle though, depends
on how effective my cooling scheme is, hoping for 5 to 10kW...

[Arlo1]

I'll post a controller build in the next few days about the 6 FET I constructed with the PCB
described in this thread. Very very cool build if I say so myself Will show you
guys how its done No clue about how much power it can handle though, depends
on how effective my cooling scheme is, hoping for 5 to 10kW...

If you place the caps where you should have in the first place it would be good for a lot more power! But you can just run the voltage at 1/2 the limits of the fets to protect them!

[Lebowski]

I'll post a controller build in the next few days about the 6 FET I constructed with the PCB
described in this thread. Very very cool build if I say so myself Will show you
guys how its done No clue about how much power it can handle though, depends
on how effective my cooling scheme is, hoping for 5 to 10kW...

If you place the caps where you should have in the first place it would be good for a lot more power! But you can just run the voltage at 1/2 the limits of the fets to protect them!

Ha ha you're funny

[MitchJi]

Hi,

Will these be available to buy and populate by people who don't know anything about electronics per se but can solder

I'd advise Lebowski to give away the controllers and charge for tech support .

[Lebowski]

Will these be available to buy and populate by people who don't know anything about electronics per se but can solder?

Cheers.

My intention is to sell small kits containing the controller IC, the power supply IC and PCB. You can then order the rest of the parts from digikey r farnell. But first I want to try to prove the design which is why I built and want to run the high power 6 FET...

[The Mighty Volt]

Will these be available to buy and populate by people who don't know anything about electronics per se but can solder?

Cheers.

My intention is to sell small kits containing the controller IC, the power supply IC and PCB. You can then order the rest of the parts from digikey r farnell. But first I want to try to prove the design which is why I built and want to run the high power 6 FET...

Thank you.