Hi,
i would like to ask for your support, to improve and check my design of PGA4311 volume controller board. This just my third in creating PCB designs.
The main goal ist to replace a existing PT2258 board, because of its sound and electrical parameters, that doesn't fit well to the needs. The DC-Offset on VDD/2 at the outputs, caused by the unsymmetrical power supply, is the primarily reason.
I had chosen the 4311 because of the 4 channels i need, low dc offset at the outputs and generally better parameters. Source are two of the cheap PCM1502 dac boards with 1kOhm Zout, sink is a preamp board for each channel, with 50kOhm Zin. The preamps have the possibility to adjust DC-offset. It would be fine to do without any coupling capacitor in signal-lines.
The board is for Layer, buttom layer is ground plane DGND, 3rd layer has a copper area for AGND, 2nd layer is mainly used for analog signal, top layer all other stuff. The footprints for coupling capacitors are for some experiments and optional to use. Also C19 is optional, i don't understand its function well. Other questions are: Are resitors in the analog signal lines before and after 4311 necessary, if coupling C are in use? What can i do to improve EMI/EMV?
The type of connectors are not fixed an will be changed to more suitable type. SPI out for daisy chain will be added.
Pleas roast me with some critics and hints. Thanks a lot.
i would like to ask for your support, to improve and check my design of PGA4311 volume controller board. This just my third in creating PCB designs.
The main goal ist to replace a existing PT2258 board, because of its sound and electrical parameters, that doesn't fit well to the needs. The DC-Offset on VDD/2 at the outputs, caused by the unsymmetrical power supply, is the primarily reason.
I had chosen the 4311 because of the 4 channels i need, low dc offset at the outputs and generally better parameters. Source are two of the cheap PCM1502 dac boards with 1kOhm Zout, sink is a preamp board for each channel, with 50kOhm Zin. The preamps have the possibility to adjust DC-offset. It would be fine to do without any coupling capacitor in signal-lines.
The board is for Layer, buttom layer is ground plane DGND, 3rd layer has a copper area for AGND, 2nd layer is mainly used for analog signal, top layer all other stuff. The footprints for coupling capacitors are for some experiments and optional to use. Also C19 is optional, i don't understand its function well. Other questions are: Are resitors in the analog signal lines before and after 4311 necessary, if coupling C are in use? What can i do to improve EMI/EMV?
The type of connectors are not fixed an will be changed to more suitable type. SPI out for daisy chain will be added.
Pleas roast me with some critics and hints. Thanks a lot.
