The XCore rev. of the USB 2.0 Audio card
Posted: Sat Apr 24, 2010 12:36 pm
I have been using the USB 2.0 Audio card for about a ½ year now, and there are also several others here that have the card.
I have several ideas of HW-layout changes for the card, and since the design files can be downloaded I would like to collect different ideas from the existing users what they would like to be improved in a future rev. of the card.
I will edit this post and paste all good ideas below:
Personally I like the low-latency anti-alias filters, making it possible to use it for DSP. So I prefer to stick to Cirrus converters.
If this turns out good I might make 10-20 prototype PCB boards (in total) and send it away for free evaluation to people here that are helping me to make it happen. (I mean it´s almost free to make extra cards, so I can give them away for free, if you help me to find things that needs to be improved). On the other hand, I will be the one that makes the final decision what to change and what to keep as it is.
List of changes:
Change the analog ground to the CODEC
Add support for 5V external power supply in stand alone mode.
Use buffered inputs with overvoltage protection, and buffered outputs supporting 32 ohms headphones (TPA152).
Change the CODEC to a one with included PGA an mic BIAS (CS4245 or CS4265).
Run the CODEC as a slave in I2C mode, including controllability over MDIV1 & MDIV2.
Add Xlink support (if possible)
Skip the multi clock layout - use Frequency Synthesis instead fed from the USB clock (CS2300)
Change to L2 chip to add much more free MIPS, if it doesnt make the PCB too complex - othervise use 2 L1-64.
Have the possibility to stack several stereo cards to add more channels. Of course not the way to do it in mass production - but good for testing.
I have several ideas of HW-layout changes for the card, and since the design files can be downloaded I would like to collect different ideas from the existing users what they would like to be improved in a future rev. of the card.
I will edit this post and paste all good ideas below:
Personally I like the low-latency anti-alias filters, making it possible to use it for DSP. So I prefer to stick to Cirrus converters.
If this turns out good I might make 10-20 prototype PCB boards (in total) and send it away for free evaluation to people here that are helping me to make it happen. (I mean it´s almost free to make extra cards, so I can give them away for free, if you help me to find things that needs to be improved). On the other hand, I will be the one that makes the final decision what to change and what to keep as it is.
List of changes:
Change the analog ground to the CODEC
Add support for 5V external power supply in stand alone mode.
Use buffered inputs with overvoltage protection, and buffered outputs supporting 32 ohms headphones (TPA152).
Change the CODEC to a one with included PGA an mic BIAS (CS4245 or CS4265).
Run the CODEC as a slave in I2C mode, including controllability over MDIV1 & MDIV2.
Add Xlink support (if possible)
Skip the multi clock layout - use Frequency Synthesis instead fed from the USB clock (CS2300)
Change to L2 chip to add much more free MIPS, if it doesnt make the PCB too complex - othervise use 2 L1-64.
Have the possibility to stack several stereo cards to add more channels. Of course not the way to do it in mass production - but good for testing.