Class D amp

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I have made a class D amp based on HIP4080 on a vero board. Modulation frequency set to 150Khz.
But the output is not so clear as compared to the class AB designs. Initially there was a DC offset which I adjusted, but still I am not satisfied with the quality of sound.
There is a little hissing sound and chiirrr__ssiiirrrr type of sound with no input and maybe it increases with the volume. Would it be cause of ringing on the gate of mosfets. There is very nominal heating on the mosfets even at high outputs @4Ohms Load and supply of 25V.
I have used IRF540 mosfets, should I use fast recovery clamping diodes with mosfets.
What else can matter the quality of the output.


Regards,
Sonu.
 
Fine..... i have made it on a vero board but layout done has been very perfect as required for high frequency, with good decoupling caps, very short traces.

As I asked earlier would it be cause of ringing on the gates, I have used 10 Ohms Resistors to gate, or what else can be the cause. As per the datasheet 150Khz is the best for efficiency & performance, increasing the modu freq would decrease the efficiency.

Has anyone made and tested this design.

Regards,
 
While you can actually check if a class-d amp is working in principle by using a Veroboard, you will have to take a double-sided PCB with a good groundplane to get the most out of it.
Have you seen that there is development kit available for this HIP driver ? The layout they use shpuld be available on the WEB.

Regards

Charles
 
Class D

The links you mentioned, they have no stock for Evaluation Boards.

Anybody there who could help in getting a Evaluation board,
----OR----
Postscipt, Gerber Files of the PCB.

I am very desparate to get it working & getting good performance from these cool Amps Design.

ANYBODY THERE.

Regards,
 
HIP4080 is quite choosy with mosfets. I've tried with IRF540, but failed. Maybe the input cap is too big. Try other/newer kind of mosfet, with lower input cap. I've tried with FDP mosfets, and works fine.
There will be always little noise/hiss, and DC offset. Usually can be made minimum, but cannot eliminate them.

It seems Intersil cant (or wouldnt) give as much support, as they have sell the technology to Behringer.
 
PCB

You cannot very easily make a quiet class D amp on a single sided board. I found ground planes are very important for quiet operation. The B&O mdules i use are done with a 4 layer PCB to get the 115db S/N ratio they have.

Also, the HIP4080 IC has a primitive single comparitor modulator that is not particularly good. Whie it is a decent FET driver, the quality of the modulator means that you have to either use an external modulator or you use this amplifier just as a sub-woofer amplifier. Many class D car amps, like Kicker use the 4080 in the sub channel but class B for the other channels.

There are some class D amp schematics available at:

www.schematicsforfree.mattsoft.net
 
HIP4080 is quite choosy with mosfets. I've tried with IRF540, but failed. Maybe the input cap is too big. Try other/newer kind of mosfet, with lower input cap. I've tried with FDP mosfets, and works fine.

I have ordered a couple of samples of HIP4080,but I could not get a hold of any HIP2060 the N chanel,halfbrigde Power MOSfets that they have,does anyone have a schema with IRF540 or FDP mosfets,Whatever they are?And what is the output with these,I am going for a sub amp for my computer or iRiver.By the way if I happend to get a hold on HIP2060 what would the outputpower be?
 
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