Nice MOSFETs for class D from IR (or how they try to impose us the DirectFet thrash)

[fumac]

Originally posted by ChocoHolic
Again many thanks for listing several interesting devices:

Does this mean that the body diodes are now designed in a way that there is really no dv/dt limit and may be they even might offer soft recovery characteristics??

i have test most of d-fets from *R
not very good at my project, running at 1mhz,
perhaps my speed is toooo fast,too high dv/dt
d-fet ,very easy to be break
but if u use the driver from ir, perhaps will work well,
because the driver from *r is slowly.
i'v never used it

rg
fumac

[poobah]

You guys are scaring me...

I just designed those Direct Fets into a prototype!

[Ouroboros]

The NXP (Philips) devices listed in their 'LV MOSFET Applications' app-note (for the UCD basic design) all appear to be good devices. Although the parts shown are TO220 and D2-PAK parts, if you look on the NXP site there are also D-PAK (TO252) versions of some of them. I'm using D-PAK devices on a fully SM class-D design of mine, (using thermal vias to conduct the heat to the other side of the pcb, where I have a heatsink attached), and the low inductance leads of this package result in a very low-noise design.

[ChocoHolic]

Originally posted by poobah
You guys are scaring me...

I just designed those Direct Fets into a prototype!

Don't worry there are many ways to kill MosFets.
Fumac's trouble might not necessarily appear in your proto. Without detailed screenshots and analysis what went wrong at fumac's place, it is impossible to translate his findings to your project.
I would say 'go on' and let us participate on your findings.

[fumac]

Originally posted by ChocoHolic


Don't worry there are many ways to kill MosFets.
Fumac's trouble might not necessarily appear in your proto. Without detailed screenshots and analysis what went wrong at fumac's place, it is impossible to translate his findings to your project.
I would say 'go on' and let us participate on your findings.

yes, keeping research, this is the only way to make ur project running .

but , my test told me , that the d-fets just can be use in a low power project,
because the heat-sink is hard to asm on it , include d-park, not easy to use at high power
i use TO-220 at all of my high power projects.

rg
fumac

[poobah]

Actually,

As far as heatsinking is concerned... these D-FETS open a lot of new possibilities.

[IVX]

IMO, to bypass body diode is much easier, than to find proper 200V mosfet.
PS: I've tried directfets 2 years ago in the caraudio 12V H-bridge SMPS, 2mOhm 30nC/13nC (though Trr isn't matter for 12VDC apps), well, i think it's really nice stuff, but very annoying was directfet replacing procedure, due to huge trafo pins, that was extremely close to the directfets. So i guess, i would be damned by repairers, and finally i throws it out. BTW, directfets heatsinking is not so convenient vs to220 ones.
PS2: "IRFZ48V 100V 36A .021ohm 42nC/41nC" hmm, rather irf540z By the way, 540z could be successfully used in the class D too, of course it isn't the best choice though. This is THD/Power sweep of amp 400kHz ir_driver+irf540z +/-36VDC, loop gain are ~36db, 4oHm loaded:

[legomanww]

I realize it's not >100V, but what about the ST micro STP36NF06L?

STP36NF06L 60V 30A 0.033ohm 13nC/107nC

would it be suitable for lower power?

[Shortcircuit]

Originally posted by legomanww
STP36NF06L 60V 30A 0.033ohm 13nC/107nC
would it be suitable for lower power? [/B]

Hi!
Good choice for +/- 30V supply !
Regards