LM 3886 PCB Based On Carlos Fm Schemetic

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#22
the direct distance from +ve power pin to -ve power pin is ~5mm.
The length of track and components around the decoupling loop is ~200mm.
If the HF decoupling is to work as intended by the manufacturer that long route must be reduced. Getting it down to 50mm would be a start, 20mm would be better.
 
#25
neeraj said:
Hi have a look on this PCB Layout.
Click to expand...

Lolzzz, may be u want to say that here i have done the same thing, This one was made by me only.. But there i am creating the ground plane on my amplifier side.. so there is no ground looping. Even ur PCB is also fine if u use the power supplied suggested by me in this layout. The power supply is not having ground plane in this case
 
#26
kuldeepsingh said:
Lolzzz, may be u want to say that here i have done the same thing, This one was made by me only.. But there i am creating the ground plane on my amplifier side.. so there is no ground looping. Even ur PCB is also fine if u use the power supplied suggested by me in this layout. The power supply is not having ground plane in this case
Click to expand...

You are right Pa Jee.have a look on my supply pcb & revert if some improvements required.
Or is it good to opt for HARD Wired amp. plz suggest

http://www.diyaudio.com/forums/chip-amps/170095-hi-cap-ps-carlos-fm.html
 
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#29
My opinion has been and remains:
One must understand how and why a ground plane works and one must use this knowledge to design the ground plane to suit the application.

If one cannot meet any of those criteria, then do not attempt a ground plane.
 
#32
AndrewT said:
I do not fully understand the how nor the why and I certainly can't design a ground plane to suit the application.
I cannot offer any assistance.
I know my limitations. I take pride in being able to recognise those limitations.
Click to expand...

Hi AndrewT,
I have seen various similar implementations on the net.
I agree with you that doing a job whose result is not fruitful is not required.
So now i am going to hard wire the complete job. i.e. Power supply & amp.
in fact one channel power supply is completed.
thanks for your help & support.🙂
 
#35
AndrewT said:
the direct distance from +ve power pin to -ve power pin is ~5mm.
The length of track and components around the decoupling loop is ~200mm.
If the HF decoupling is to work as intended by the manufacturer that long route must be reduced. Getting it down to 50mm would be a start, 20mm would be better.
Click to expand...
do you remember this post?

I cannot offer any better than that.
 
#36
I'm working on a 3886 PCB design at the moment. You can place the smaller decoupling power capacitors left of the chip where the power pins (1,4,5) are located without difficulty - within 20mm. Don't be afraid to use narrower tracks or lose symmetry to get all the components as close to the chip as physically (and safely) possible. Your design is much neater than mine (damn it!) 🙂
 
#38
godfrey said:
Something easy to fix:
Cz (the zobel capacitor) should be connected to power ground, not signal ground.
So on the PCB it just needs to be moved slightly so that it goes to the left or down, instead of to the right.
Click to expand...

Hi ,

Kuldeep Singh PA Jee : Thanks.
AndrewT : Yes i remember that post. You are A good teacher for students like Me. Perhaps i um unable to understand the seriousness what u are talking about n will be glad fi you please explain. As told Low res photograph of
3.3mfd/100volt will be mounted directly on chip pins.my supply PCB
Random: Thanks for such appreciating words. i am working on your suggestion.
Godfrey: Thanks for the Hint.Actually Cz is connected to Power ground but the trace connecting star groud power & Power G was missed.
Now i have corrected the layout.
 

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#39
looks Cute... 🙂 Good work... neeraj...
I am too going to start a PCB for the same chip AMP. Can you tell me what pcb tool did u use?

And thanks to other members here for giving valuable tips. Sure this would get me success too.

http://www.national.com/an/AN/AN-1192.pdf

referring above application note I wish to go for BR100 configuration.
I have plans to use two smps rating 4 amp 20V DC for dual supply. This would reduce the size of filter capacitor. Also this supply is readily available in market at cheap ,as used for Laptop supply. saving cost and efforts.

Need comments on my approach.
 
#40
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