The output port on that board is configured as master which requires an external MCK (crystal or clock). In master mode MCK and output fs are related (MCK = 64fs/128fs/192fs/256fs/384fs/512fs/768fs). So in my board output fs is always 48k (or multiple). If you need also 44k1 fs (or multiples) then you need another clock and some clock selection circuitry. The clock on that board was NZ2520SDA.
I've long since moved to USB input so I'm not using that AK4118+AK4137 board anymore. I replaced it with a small "standalone" pin control only AK4118+AK4137 board with SPDIF/optical input.
I've long since moved to USB input so I'm not using that AK4118+AK4137 board anymore. I replaced it with a small "standalone" pin control only AK4118+AK4137 board with SPDIF/optical input.
Ok, it's more clear now thanks 🙂
If I feed AK4137 with only a 24.576 clock then I2S out will only be 48k family Fs. And if SPDIF is 44.1k then AK4137 reclock to 48k right ?
I can generate both clock (I plan to use the open UAC2 bridge with stm32f446 which can generate both clock on other thread)
Will be interested in your standalone pin control circuit to avoid another I2C to manage.
Other interesting thing for me: what is your usb bridge today ?
Thanks to help me in the field of digital audio 🙂
If I feed AK4137 with only a 24.576 clock then I2S out will only be 48k family Fs. And if SPDIF is 44.1k then AK4137 reclock to 48k right ?
I can generate both clock (I plan to use the open UAC2 bridge with stm32f446 which can generate both clock on other thread)
Will be interested in your standalone pin control circuit to avoid another I2C to manage.
Other interesting thing for me: what is your usb bridge today ?
Thanks to help me in the field of digital audio 🙂
Yes, with 24.576MHz MCK AK4137 will reclock output to 48k family fs.
I have been using my own STM32F7/H7 based USB-I2S boards since 2021. More info on earlier versions e.g. here.
Actually my memory failed me as my current AK4118+AK4137 board uses I2C so it is not pin control. But I have a pin control only AK4118 board (without AK4137).
I have been using my own STM32F7/H7 based USB-I2S boards since 2021. More info on earlier versions e.g. here.
Actually my memory failed me as my current AK4118+AK4137 board uses I2C so it is not pin control. But I have a pin control only AK4118 board (without AK4137).
Parallel mode (pin control) with AK4118+AK4137 is quite straightforward. You need pin headers with pullpup or pulldown resistors on these pins:
AK4118:
IPS0-1
DIF0-2
OCKS0-1
CM0-1
AK4137:
IDIF0-2
SLOW
SD
CM0-3
OBIT0-1
ODIF0-1
In addition you need a PDN circuit (common to AK4118 & AK4137). Simple RC with Schmitt trigger works fine.
AK4118:
IPS0-1
DIF0-2
OCKS0-1
CM0-1
AK4137:
IDIF0-2
SLOW
SD
CM0-3
OBIT0-1
ODIF0-1
In addition you need a PDN circuit (common to AK4118 & AK4137). Simple RC with Schmitt trigger works fine.