PCM1808: Affect by system clock

Kuramochi Tadahiko

Guru 28715 points

Part Number: PCM1808

Hi,

My customer considers using PCM1808 and the sampling frequency is 48kHz.

Are any characteristics differences in the case of setting fsclk=2.048MHz or 4.096MHz?

Best Regards,

Kuramochi

over 5 years ago

0 Collin Wells over 5 years ago

TI__Guru 64335 points

Hello,

The PCM1808 supports 256fs, 384fs, and 512fs options, so with a 48kHz sampling rate the main clock input needs to be 12.288MHz - 24.576MHz.

More information can be found in Section 7.3.2 System Clock and Table 1.

0 Kuramochi Tadahiko over 5 years ago in reply to Collin Wells

Guru 28715 points

Collin-san,

Thank you for your support.

Are any characteristics differences in the case of setting fsclk=12.288MHz or 24.576MHz at fs=48kHz?

Best Regards,

Kuramochi

0 Kuramochi Tadahiko over 5 years ago in reply to Kuramochi Tadahiko

Guru 28715 points

Hi Collin-san,

How is the situation?

Best Regards,

Kuramochi

0 Zak Kaye over 5 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 23050 points

Hi Kuramochi-san,

Collin is out for the day so I will answer.

There is no impact to performance using one SCLK vs. the other. You may prefer to use a lower frequency SCLK from an EMI perspective and/or depending on board layout and trace lengths lower frequencies may be preferable, but the PCM1808 performance does not change assuming the clock is clean in both cases!

Best,

Zak

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PCM1808: Affect by system clock