I'm now going to order prototypes of the DAC pcbs as soon as I have found a good source for the PCM4104 in small quantities.
here is the layout of one DAC module (4channels).
- the +5VA trace running under the chip makes a nasty moat in the ground plane. I would suggest either stitching the top-layer ground under the chip to the plane with a few vias, or even using a single jumper wire and keeping the ground plane unbroken (ugly but functional).
- I wonder what happens wrt ground loops given that you have grounds connected at both X101 and X1001
- consider removing some of the ground plane right below the inputs of the op-amps and their associated traces, this will help stability especially with faster op-amps.
- those capacitors marked X7R will be C0G/NP0 in the final version, right?
It looks interesting, but definitely not a soldering project for the average DIYer.
Quote from: jdbakker on September 23, 2009, 08:46:55 AM- consider removing some of the ground plane right below the inputs of the op-amps and their associated traces, this will help stability especially with faster op-amps.Never seen that on a solid ground plane.
Quote from: jdbakker on September 23, 2009, 08:46:55 AMIt looks interesting, but definitely not a soldering project for the average DIYer.Hey, come on. Its only 0805 and TQFP. My first soldering projects have been already made with these case types. It is not so difficult like it seems to be. You need to know two or three tricks.
I agree it becomes very hard or impossible when we want to use BGA or packages without exposed pins. But these types I normally avoid because I know that I cannot solder them myself.
if this project really gets going, I may be of some help... my father owns a circuit board manufacturing company (which I have worked in), with solder paste screening, pick and place machines, and a couple of reflow ovens.