Ultra Simple Class D

[lehcim74]

lehcim74, I would really like to have a pcb if its possible, if yes please tell me a price, otherwise can I have the schematic including the power supply? I would really love to use it for car too! Keep up your great work 🙂

Hi Omokas,

Amplifier is still work in progress but the power supply is working OK.
Still intend to use it for mono subwoofer amplifier and trying some different
active pre-filters.

PSU is according PDF document attached.
Full schematic.pdf is with the class D amp.
(filter still needs some tuning to my believe)

PSU is made with ETD39 TDK PC40 material.
NP1=NP2= 5Turns
NS1=NS2=14Turns = about ±35V

(Mostly used smd parts on controlboard, that is why there are many 1P connector items used.)

 

[Mondan]

This topic is long and difficult to follow.
However, regard only the scheme of post #139, pg. 14 (this topic).

If it's class D, can you put MOSFET driver?

 

[pergo]

I have done try this amp, but i have a problem with DC offset,
i got -65mV and -54mV at other channel,
please help for reduce this DC offset,

BR//
Madde

They're good enough

 

[lelut]

They're good enough

Thanks sir for your answer, its save for speaker sir?

 

[stewin]

merry CHRISTmass to you all 😀

 

[FETBurner]

Hi all,

i tried to get this amp working on a breadboard. I'm not sure if that makes sense at all because of the about 300kHz switching freq.
I run the amp at about +/- 33V with all components like the original schematic.
For very low input signals i can get about +/- 3V clean output signal at 4 ohms load.
When i try to go higher with the input the output gets distorted and lots current is drained from my negative power supply but output voltage remains the same. Only more and more noise.
The inductor gets pretty warm too. I tried about 30uH ferrite and iron powder cores, about the same problem.

An externally hosted image should be here but it was not working when we last tested it.

PMOS gate signal: AC coupling, 5V/div, 1µs/div

An externally hosted image should be here but it was not working when we last tested it.

NMOS gate signal: Same settings

An externally hosted image should be here but it was not working when we last tested it.

Low level output signal: DC coupling, 2V/div, 0.2ms/div

An externally hosted image should be here but it was not working when we last tested it.

Low level output signal noise: DC coupling, 2V/div, 2µs/div

An externally hosted image should be here but it was not working when we last tested it.

Higher level output signal: DC coupling, 5V/div, 0.2ms/div

If you need more measurements i will provide them as soon as possible.

 

[sweetperfume]

Hi all,

i tried to get this amp working on a breadboard. I'm not sure if that makes sense at all because of the about 300kHz switching freq.
I run the amp at about +/- 33V with all components like the original schematic.
For very low input signals i can get about +/- 3V clean output signal at 4 ohms load.
When i try to go higher with the input the output gets distorted and lots current is drained from my negative power supply but output voltage remains the same. Only more and more noise.
The inductor gets pretty warm too. I tried about 30uH ferrite and iron powder cores, about the same problem.

An externally hosted image should be here but it was not working when we last tested it.

PMOS gate signal: AC coupling, 5V/div, 1µs/div

An externally hosted image should be here but it was not working when we last tested it.

NMOS gate signal: Same settings

An externally hosted image should be here but it was not working when we last tested it.

Low level output signal: DC coupling, 2V/div, 0.2ms/div

An externally hosted image should be here but it was not working when we last tested it.

Low level output signal noise: DC coupling, 2V/div, 2µs/div

An externally hosted image should be here but it was not working when we last tested it.

Higher level output signal: DC coupling, 5V/div, 0.2ms/div

If you need more measurements i will provide them as soon as possible.

Post your pcb image bottom side and component side

 

[kinter]

Hi to all, this is my final amplifier SMPS +class D + speaker prot. It is working fine from several months.

 

[thimios]

Hi to all, this is my final amplifier SMPS +class D + speaker prot. It is working fine from several months.
View attachment 490173

Nice work!
Where we can find the schematic and pcb as built?

 

[stewin]

nice work and excellent job kniter . did you include a protection circuit.

 

[kinter]

Not overcurrent, only speaker protection with relays

 

[sweetperfume]

hello sir stewin,
is there any way to use this design at +/-50 volts?
mine worked for the voltage with original components but after a week started to fail. my pcb is double sided with dc protect. with 45volts it works fine but if i touch the volume pots on board then positive side mosfet dies burning output tracks and before dying it makes some sort of grunting noise. what maybe the issue?

 

[Deleted member 148505]

Currently working on 250W @ 4 ohms version using IRF6218/IRFB33N15D.
Reworked protection circuit, high/low side protection. Double sided PCB.

Will share schematics after I tested the prototype. 🙂

 

[Deleted member 148505]

PCB design sample

2.6 x 5.0 inches

 

[stewin]

wow nice work. pls post the project or the schematic.

 

[PRAPORSHIK666]

hello! how is dead time?

 

[stewin]

hi all finally smd version completed :UP: 😀😀
instead of bc337 and 327 i used mmbt 3904 and mmbt 4403 any comments are highly appreciated

 

[omokas]

hi all finally smd version completed :UP: 😀😀
instead of bc337 and 327 i used mmbt 3904 and mmbt 4403 any comments are highly appreciated

Dear stewin could you please share schematic or pcb layout files?

Much appreciated!!

 

[stewin]

😎hi all finally smd version completed :UP: 😀😀
instead of bc337 and 327 i used mmbt 3904 and mmbt 4403 any comments are highly appreciated

but mmbt5401 and mmbt5551 i have and i will use. i use tl074 from ti (texas instruments) as they are the only ones which work with this circuit.

 

[omokas]

Thank you very much for your work!

How much current does the 30uH must be able to withstand? and frequency?