Two ISOTOP mosfets...and other things

http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00222025.pdf

imgur: the simple image sharer

These would be great for a SSTC, DRSSTC or something similar. US only please.

I'm asking $12 per or $21 for both.

I have a few other semiconductors, if you need something specific please ask, and I'll dig around to see what I can find. MOSFETS, transistors, whatever.

Thanks for looking. :na:

Nice, built in zener regulation on the Gate! 10mOhm RdsON too. Looks like it is quite high gate capacitance though, what chips would be needed to drive this at a respectible frequency (say... 800KHz)? I'm not familiar with gate drive chips which can source more than 2.5A, and these fets look like they'd want more than that. This is something to consider if marking the item as SSTC/DRSSTC ready, as only large coils would operate in the low 100's of KHz. If the Gate is going to require a lot of current it may need to be fed with an IGBT brick gate driver, as those are designed to deal with large gate capacitances.

11 nF's of gate capactiance, yes, they are indeed chunky.

You could probably either 1. Design your own driver stage using discrete transistors, OR,
2. Use UCC37322 or UCC37321 pairs. They are conplementary gate drive IC's (one is inverting, other is noninverting) and they can push out a sexy 9 amps peak into mosfet gates. If you parallel them it gets even higher.

As for max frequency, I wouldn't attempt anythin over 400-500 khz with these.

I do have faster ones though.

Ahh, I am a little familiar with the UCC37322/1 complementary GDICs! I did not know they were rated for 9Apk though, and had no idea they could be paralleled. For some reason I was thinking they maxed out at 2.5A... maybe I was mixing it up with a TC4420...

Hmm, 500KHz isn't too bad for a medium sized coil. Would definitely be doable if you use a larger topload.

Got a related question for ya, if ya don't mind... what is the current sink to source ratio for gate drive ICs? I would assume that based on fundamental current laws Iout = Iin, yet I never see designs where GDICs are fed with high current sources. Is it because they only draw the huge current for a short period of time or what? It's pretty common to feed a UCC37322 with a LM7812... which can only source 1A! Though in most common designs they're not driving brick fets, haha.

If I were to drive these fets with UCC37322/1 in half bridge formation, how much current should I design the gate drive rail to supply assuming a high frequency of 400KHz?

IIRC: I = C * dv/dt
I = 0.000000011F * 20/0.0000025
I= 0.088A - that doesn't sound right, I am still new to this stuff though...

dt = 1/frequency right?

You have to remember, it's just PEAK current draw. Think of how a capacitor charges up.

You also have capacitance on the supply rails, right? Capacitors can supply a big amount of current for a short amount of time. Perfect for driving a fet or IGBT's gate. And, the UCC IC's are actually half bridges in each chip, one just inverts while the other doesn't.

Haha, DUH, yes I forgot about the supply rail filtering caps, haha.

Well, if these fets are still available once I start my new job I'll take them off your hands, and any GDT cores you have as well.

I doubt they're going anywhere. :na:

bump!