Hi all! I would like your opinion on my first try at designing a PCB for Audio. I'm a software guy who has done some digital circuit design, but I have almost no experience with analog design.
This (part of the) PCB is supposed to convert a digital stereo audio signal (coming from my own circuit within an FPGA) into analog for output on unbalanced line level connectors. I'm using the Wolfson WM8521 DAC.
The surrounding components are basically taken from the example in the datasheet. As decoupling capacitors I have picked 10uF WIMA MKS-2 because I read a few times that they perform well for this application and they don't dry out unlike electrolytics. The others are just generic 0805 parts.
The DAC needs 9V, so I've picked a generic (7805) voltage regulator. All the rest is 3.3V. Maybe some more thought should go into the voltage supply but then again, I have no clue about that stuff.
It's a 2 layer PCB (red = top, blue = bottom). Following the advice from Wolfson's white paper about grounding, I have seperated the audio part from the groundplane shared by the rest of the PCB. The only connection point is under the DAC. There is actually an audio ground plane on either side. They are connected through the vias and the through-hole parts (decoupling capacitors and connectors). Directly below the decoupling capacitors, there is an unrelated header which is not connected to this ground.
The vertical red line on the DAC is just a handle of the underlying groundplane polygon. The MCLK pin is connected to the BCLK pin since I use the same clock for both.
I'm not aiming to build an ultra-high-quality device here, but it should be on-par with good consumer electronics.
The second image is a zoom of the first one.
Thanks for your help!
This (part of the) PCB is supposed to convert a digital stereo audio signal (coming from my own circuit within an FPGA) into analog for output on unbalanced line level connectors. I'm using the Wolfson WM8521 DAC.
The surrounding components are basically taken from the example in the datasheet. As decoupling capacitors I have picked 10uF WIMA MKS-2 because I read a few times that they perform well for this application and they don't dry out unlike electrolytics. The others are just generic 0805 parts.
The DAC needs 9V, so I've picked a generic (7805) voltage regulator. All the rest is 3.3V. Maybe some more thought should go into the voltage supply but then again, I have no clue about that stuff.
It's a 2 layer PCB (red = top, blue = bottom). Following the advice from Wolfson's white paper about grounding, I have seperated the audio part from the groundplane shared by the rest of the PCB. The only connection point is under the DAC. There is actually an audio ground plane on either side. They are connected through the vias and the through-hole parts (decoupling capacitors and connectors). Directly below the decoupling capacitors, there is an unrelated header which is not connected to this ground.
The vertical red line on the DAC is just a handle of the underlying groundplane polygon. The MCLK pin is connected to the BCLK pin since I use the same clock for both.
I'm not aiming to build an ultra-high-quality device here, but it should be on-par with good consumer electronics.
The second image is a zoom of the first one.
Thanks for your help!
