TAS5548/58 I2S Serial Output at 48kHz Irrespective of Input Sampling Rate

Sadanori Kato

Other Parts Discussed in Thread: TAS5548

Hi,

There is mentioned in the data sheet about the I2S serial output as below.
Is the I2S serial output fixed 48kHz if using MCLK : 12.288MHz(fixed), the input sampling rate : from 32kHz to 48kHz ?
if the I2S serial output is fixed 48kHz without depending on it, how does TAS5548/58 realize this feature ?
Could you please tell us the internal topology in detail ?

Bestregards,
Kato

over 8 years ago

0 Sadanori Kato over 8 years ago

Guru 36490 points

Hi,

We have an additional information.
We found that the I2S serial data depends on the input sampling rate when verifying TAS5534/38 regarding the SDOUT mode.
Have TAS5548/58 already been improved it as it is mentioned in the data sheet ?
Could you please tell us the internal topology in detail if having been improved ?

Best regards,
Kato

0 Justin Bohr over 8 years ago in reply to Sadanori Kato

TI__Mastermind 27850 points

Hi Kato-san,

The SDOUT for the TAS5534/38 was dependent on the input sampling rate. However, the TAS5548/58 has 2 ASRCs which allow the TAS5548/58 to take any sampling rate up to 192 kHz and convert it to any sampling rate. For the case of SDOUT, the ASRC will convert to 48 kHz. Since there are two ASRCs, this operation can be done.

Justin

0 Sadanori Kato over 8 years ago in reply to Justin Bohr

Guru 36490 points

Hi Justin-san,

Thank you for your response.
I have an additional question.
I understood that the I2S serial output is fixed to 48kHz without depending on the input sampling rate, on the other hand the master clock output(MCLKO) always is generated from the MCLK input or XTAL input.
Is my understanding correct ?

Best regards,
Kato

0 Justin Bohr over 8 years ago in reply to Sadanori Kato

TI__Mastermind 27850 points

Hi Kato-san,

I will set this up and test this in the lab to verify the operation.

Justin

0 Justin Bohr over 8 years ago in reply to Justin Bohr

TI__Mastermind 27850 points

Hi Kato-san,

So it seems that yes MCLKO is generated from the MCLK input or crystal frequency, but passes through the ASRC and will always output 12.288 MHz, but in register 0xC5, you can choose to divide the output by 1, 2, 4, or 8. You can also change the output sampling rate to the internal sampling rate (96 kHz).

Justin

0 Sadanori Kato over 8 years ago in reply to Justin Bohr

Guru 36490 points

Hi Justin-san,

Thank you for your strong support.
I understood and will inform our customer of your information.

Best regards,
Kato

Audio

Audio forum

TAS5548/58 I2S Serial Output at 48kHz Irrespective of Input Sampling Rate