TAS1020B-based Asynchronous USB to I2S/SPDIF converter 24bit/96kHz

[robertopisa]

Are you planning to have also AES/EBU - XLR output?
Thanks
Roberto

[gabanyayaya]

Originally Posted by JarekC

Hi

USB to I2S module (STAGE1 specification, assembled & testet)
cost about 40$ + shipping

USB to SPDIF(COAX) module (STAGE2 specification, assembled & testet)
cost about 60$ + shipping

I never not send parcels outside the EU, so I don't know shipping cost.
I have to check this.

Version with externals oscillator is not available now because of problems with purchase of 22.5792MHZ oscillators in a small amount.
Mouser and Digikey stocks are empty.

If anyone knows a supplier for 22.5792MHz oscillators (SMD 7mmx5mm, 3.3V, 20-25ppm) in good price, I will be grateful for information

Best regards
JarekC

JarekC

can you describe the performance for this convertor starting from stage 1 version to stage 4 version ? is it better towards the best performance......???

[JarekC]

Hi,

The PCB is ready for AES/EBU-XLR output.

Additional parts for this option:
-XLR Connector (mounted outside the PCB)
-PE65612 transfrmer
-DS26LV31 driver
-110 Ohm 0805 resistor
-100nF 0805 capacitor

Best Regards
JarekC

[robertopisa]

Interesting, thanks
-Roberto

Originally Posted by JarekC

Hi,

The PCB is ready for AES/EBU-XLR output.

Additional parts for this option:
-XLR Connector (mounted outside the PCB)
-PE65612 transfrmer
-DS26LV31 driver
-110 Ohm 0805 resistor
-100nF 0805 capacitor

Best Regards
JarekC

[robertopisa]

As I wrote, it is an interesting project. But why mini-USB? People might have invested on USB A-B cables...

Is it supporting USB Audio 2.0 like the XMOS Reference Design?

Thanks again
Roberto

Originally Posted by JarekC

Hi,

I designed an additional PCB layout with galvanic isolation (ADUM4160/3160).
The PCB is mounted instead of USB connector.
On the new PCB there is new USB mini connector.
TAS1020B controls the signal PIN of ADUM4160.
ADUM can be powered from 3.3V or from external power supply.

Bellow schematic.

Best regards
JarekC

[JarekC]

In the standard version there is USB-B socket.
On the main PCB there no place for ADUM, so I add special doughter board.
After the addition this board there is no space for USB-B so I used USB-Mini socket.
I'm waiting for this doughter boards (planned delivery date March 2).

TAS1020B have USB Full Speed USB Interfece (12Mb/s) and supports only USB Audio Class 1.0

I plan to design new PCB with isolation and fitted in Harmond Alu case.

I also plan to design version with USB Audio Class 2.0 based on TI DSP C5xxx.

In XMOS I/O pins are reclocked with 400Mhz, this I do not like.

Best regards
JarekC

[robertopisa]

Thanks for the clarification, I stay tuned for the USB 2.0 version, I would like to order one with AES/EBU.

Cheers
Roberto

Originally Posted by JarekC

In the standard version there is USB-B socket.
On the main PCB there no place for ADUM, so I add special doughter board.
After the addition this board there is no space for USB-B so I used USB-Mini socket.
I'm waiting for this doughter boards (planned delivery date March 2).

TAS1020B have USB Full Speed USB Interfece (12Mb/s) and supports only USB Audio Class 1.0

I plan to design new PCB with isolation and fitted in Harmond Alu case.

I also plan to design version with USB Audio Class 2.0 based on TI DSP C5xxx.

In XMOS I/O pins are reclocked with 400Mhz, this I do not like.

Best regards
JarekC

[JarekC]

USB Audio Class 2.0 besed on TI DSP, it is now only at the planning.
TI DSP C5xxx is difficult to use for DIY beacuse of uBGA case.

Now I focuses on TAS1020B, its realy good chip.

JarekC

[excelon]

Perhaps you should check this document first before saying such an error:

Originally Posted by JarekC

In XMOS I/O pins are reclocked with 400Mhz, this I do not like.

Look at Figure 8 at page 24 (posted below) to see that I/O ports in XMOS processor are driven by external audio master clock (one of two available - depending on incoming sample rate). 400 Mhz is the running frequency for the processor's internal threads. Moreover, I2S signal's retiming should not be done using a multiple of 44.1 or 48 KHz freq.? .. like 22.5792 || 24.576 Mhz OR 45.1584 Mhz || 49.152 Mhz. How above frequencies would fit in 400 Mhz or you think that XMOS has implemented some sort of ASRC at outputs

[JarekC]

Originally Posted by excelon

Perhaps you should check this document first before saying such an error:

Look at Figure 8 at page 24 (posted below) to see that I/O ports in XMOS processor are driven by external audio master clock (one of two available - depending on incoming sample rate). 400 Mhz is the running frequency for the processor's internal threads. Moreover, I2S signal's retiming should not be done using a multiple of 44.1 or 48 KHz freq.? .. like 22.5792 || 24.576 Mhz OR 45.1584 Mhz || 49.152 Mhz. How above frequencies would fit in 400 Mhz or you think that XMOS has implemented some sort of ASRC at outputs

Hi.

You are not right.
Look at:
https://www.xmos.com/download/public...8X1373A%29.pdf
In a description of the clock block in section 3.4 you find:
"Note that any external clock is itself clocked-in using the 400 MHz core clock."

Confirmation of this can be found here (XMOS technical forum)
XMOS Support Board • View topic - External clock

Respond of Larry XMOS employee:

"Yes, any external clock is resampled to 400MHz
If you tie I2S signals BCLK LRCLK and DATA to a low-jitter external
clock on the XMOS device, this will introduce a jitter in the order of
one to two 2.5ns (400MHz) cycles"

Another confirmation of this is that SPDIF out on XMOS reference board is reclocked with MCLK (U1 NS7SZ175 chip)

Best Regards
JarekC