Hardware for SPDIF out of a STM32F7 soc?

JMF11

Member
2013-12-22 6:40 pm
Hello,

I consider have a look to implementing USB audio => software DSP => SPDIF for a active multi amplification project using a STM32F7 development board

I did not succeeded for find in ST documentation the hardware to add from the SPDIF pis of the controller to the RCA SPDIF out plug.

Would you know where I could find those information and schematics ? For information, I only need to have 20 cm between the board and the amps.

Note: I have already a STM32F4 board with I2S outputs, but I did not identified cheaper/easier options for SPDIF output, than buying another development board with SPDIF already included. I'm interested in easy I2S to SPDIF possibilities if any.

Best regards,

JMF
 

JMF11

Member
2013-12-22 6:40 pm
Thanks gwing2,

Good to know. I have now in front, of me several design options to solve my problem.

I would still be happy to understand how to build the SPDIF output from a microcontroller that supports the feature. I understand that it is not just pluging the RCA connector to the STM32 pins...

JMF
 

JMF11

Member
2013-12-22 6:40 pm
Hi,

Here is the result of my seach.

I intend to use for first trails a basic schema from the WM8805 (http://www.cirrus.com/jp/pubs/proDatasheet/WM8805_v4.5.pdf)
See below

I got interesting information from AM335x McASP SPDIF output schematic - Sitara Processors Forum - Sitara? Processors - TI E2E Community with a buffer.

All basics in epanorama.net/S/PDIF Interface

I calculated that it should draw 13 mA with a 3.3V powering of the STM32, that seems compliant with the 25 mA limit.

Comments welcomed.

JMF
 

Attachments

  • WM8805 SPDIF.JPG
    WM8805 SPDIF.JPG
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