UcD like topology amp.

[luka]

Hi

Would you remake one with standard fets? Coz those that you used, would need to be ordered, if I even could... But for low power you can use many fets that are pretty old nowdays, but work great

Yet again, outstanding work, since you can put TLs in instead of ADs

[RX5]

of course it could be replaced with -some- nice opamps for buffers...

and it has been discussed on and off this forum a few years(3?) ago..I think your aware of that

the ussual buffers in the menu was NE5532 and the "AD"s ....but nowadays, there are many -much better- opamps out there to use...

[EnvisionAudio]

Well, it isn't anything out of the ordinary or unusual - but it's exactly what I was looking for - except that I've already built them.

But thanks anyway.

[iwan_audio]

Dear Bender,

very nice. Excatly, what i was looking for. And the documentations is perfect.

Do you think, i can replace the output coil by a ring-core? Any negative impact to fear?

Is the power limited by the Mosfets only? Can i get more power by bigger Mosfets, Caps and Coil?

Thanks

[Bender.ru]

Hi iwan_audio.

Using PS with 40-45V per rail you can obtain 200W @ 4Ohm using irfi42112 or irfi4019, there is no need in other changes (maybe reset OCP thresholds) and don't forget about proper heatsink . It's also possible to replace output inductor by ring core choke, you can find all necessary information in this forum.

[Kay]

Very nice work, Bender.ru!

I have a question, why is R21 referred to GND and not to
COM, as shown in the datasheet from IRF?

[Bender.ru]

hmm, let's think together . What is going on if you connect R21 at drivers COM pin?

R21+VD5 act as power supply for low side driver.

[Eljo]

Nice work Bender.ru

I will build a similar concept with IRS20955. Your schematic is
good input.

@Kay

If you connect R21 to Com you will have charging current for C12 and therefore no voltage at VCC.
Current through R21 can be calculated very easy
(40V-VD5)/R21=(40V-15V)/1500Ohm=16,6mA
Power loss in R21 Pv=416mW. So 500mW resistor is o.K.

[Kay]

thanks Bender.ru + Eljo

R21+VD5 act as power supply for low side driver

of course

but in the datasheet we find a two resistors providing
"DT", one to VCC and one to the negative rail.
You fix DT to "DT1"? (Table1, page 15 on datasheet)
If I'm not completly stupid now, why do you do this?
If I use other Fets, I must change this?

@Eljo
please post your design too

[Bender.ru]

There is no need in DT>15nS, if you want use fets like IRFI4xxx from IR.