UCD 25 watts to 1200 watts using 2 mosfets

A good mosfet for class d would be IRFB4615, low gate charge and low RDS(on).

:yes:

Definitely one of the preferable types for classD.
Besides low gate charge and low RDSon it has a good body diode with low Qrr and also IR specifies a high dv/dt rating.

From my conservative view it is fine for rails up to +/-65V.
Considering +/-65V and switching frequencies around 400kHz it can easily feed 4R loads from a half bridge and still has good headroom for impedance dips of the load.
 
3kw 0.5 ohms

complete my pcb 3kw 0.5 ohm
 

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That will not work, the DS junction need to be as short as possible.

Instead draw a big fat trace all the way from the output inductor to the gate driver, then draw as fat traces as the foot print allows from the fets down to the big fat trace.

Like i did in the layout i posted a few posts up.
 
current rating its depend what type of mosfet you are using, 20-30 amp is enough.

...mostly true.
In classD the limitation often is not given by the current rating, but more by the switching losses and Rth of the MosFet.
Consequently a MosFet with good body diode and low Rth, but not impressive current rating, can easily outperform (also in terms of amp power) a stone age monster with poor body diode.
The higher your fs, the more this will apply.
 
hi all i am making at least a supply to reach 2.5 kwt with o.c protection just about to finish . any ideas would be highly appreciated:D:D
 

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Hi guys..

so I've just finished IRS1500..but there is also a problem :(

please watch this video :

Class-D IRSD1K5 - No & Low Level input Problem - YouTube

when i turn on power supply..after s short delay , speaker connected to amp's out. as you can hear in video , there is a noise available at output. (input volume = 0) and when i increase volume up to 4~5%, a really bad audio signal become appear. also the active led indicator isn't bright constantly.
when i increase the volume (about 7~8 %) the amp start to oscillate and those problem solved.

guys please help me. anyone have similar problems ?

Regards,
IRSound


hi IRSound ,i know your problem ,

change you IC CD4049 with other manufacture

i have same problem like you
and result are ok change IC CD4049 with ST manufacture ,before TI manufacture.
my irs can work at minimal 15 volt supply with out change RSS (6,8k)

regards,

Reno