My first GC PCB drawing...

[flying]

Hi~ Today I finished the artwork of my fist GC pcb.
It is non invert circuit for LM3886 and I will cut the NC pins so I didn't include that pins.
The supply voltage is ¡¾25V. Should I use transformer which has secondary voltage about 18V?

Could anyone check this pcb?

[Franz G]

My two cents / suggestions:

I would

- turn the big caps by 180 degree to place the groundplane in the middle. Here, currents are flowing.

- try to make the traces for Vcc+/- as short as possible eg. dont put the big caps so far away from the chip as you did.

- make the traces for Vcc+/- wider.

Franz

[theChris]

also:

i try to leave space for a mounting bar that evenly applies pressure to the IC. this means less components at the top of the board.

i try to include the 100nF bypass caps.

i try to make all high current traces (output, Vcc, Vee, Ground) large.

Make sure C2 is actually that size

I try to avoid mounting the IC on top of other components.

I also try to put all the pins on the board. on your board, the user must clip off many of the back pins.

logistically, it makes more sense to place all connectors at one edge of this board. though such is not required.


these are just small to modertate things. the thing should work as is. of these, the biggest is with the high current traces.

[edjosh23]

nice boards!

I'm interessted in design a PCB, what is a good preferably free software?

Thanks,

Josh

[thomas997]

Originally posted by edjosh23
nice boards!

I'm interessted in design a PCB, what is a good preferably free software?

Thanks,

Josh

PCB Design Software

[flying]

Thank you for advice..^^
I have modified my artwork a little.

First of all, I turned the capacitor in power line.
2nd, I moved them and Vcc +/- to make trace short as Franz's sugestion.

And theChris, I'll mount R4 on the bottom. I mounted R4 on the top for convenience of drawing.^^

I usally use eagle light. There are some limits to use, but it has many lib and it is easy both to use and to make lib.


Because I'm a novie, I'm waiting for your advice! thank you.

[pinkmouse]

I would run a seperate trace back to the main ground for the OG, rather than grouping it with the others. In fact, it wouldn't hurt to split all the grounds out and run them back seperately.

[Franz G]

Flying:

When you turn now the lower cap by 90 degrees anticlockwise you will get the positive voltage track in the same length (shorter than now) as the negative track.

I would make the voltage traces still larger. And the same applies for the output trace: as large as possible!

Maybe it is a better point to connect the negative side of the speaker in the middle between the big caps.

Franz

[digi01]

to flying,
hello,far away north
your design is good.

- turn the big caps by 180 degree to place the groundplane in the middle. Here, currents are flowing.

straight up.this is my design,wish it helps.
http://www.diyaudio.com/forums/showt...399#post541399

ZANG