Parallel LM3886 Chipamp layout (PA100)

[zei]

So i honestly stolen this design from the www and made a layout.
No point in inventing the wheel again and again.

The layout is starting to look nice but i could always use a few more eyes to spot the erros.

Schematic.

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

And the layout.

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

What say you all?

/JZ

 

[AndrewT]

That's not bridged.
It is parallel.

AND
look at the length of the undecoupled power rails!
Does that long power ground rail realise low inductance?

 

[zei]

AndrewT, Of course it is,, Thanx!

And thanx for commenting

Mmm. Well they are not that long, about 30mm between caps and screwterminals, And as you see, they can very easy be made shorter.

Noticed and i,ll fix that in the "mix"

Nothing more AndrewT?

/JZ

 

[AndrewT]

.....they are not that long, about 30mm between caps and screwterminals,.....

How long is it between the rightmost 100nF decoupling cap and the leftmost power pin of the left hand chipamp?
The other power pins are similarly crippled.

Do you really need parallel? Change to efficient 8ohm speakers.
What about the tolerance of the matching components to allow parallel to work correctly?

 

[zei]

Mmm.. you are right, it is abit long. I,ll see if i can shorten it as much as possible.

matching components should,nt be that difficult.

I get the feeling that you think the parallel chipamp is a bad idé all in all? It seems to be kind of popular to build

/JZ

 

[MJL21193]

The decoupling can be tacked on the bottom afterwards if needed. I see the power leads are very thin and this goes against the idea of these paralleled to handle more current.
Running between the pins on the footprint of the LM doesn't give much room. Better to move these in order to make them wider.

 

[zei]

Thank you MJL21193.

I,ll see what i can do

/JZ