DIT4192 128fs support

EKiN BiNAL

Other Parts Discussed in Thread: DIT4192, PCM1681

We have an audio board design that takes I2S and outputs in parallel with a DAC (PCM1681) and DIT4192s. The DIT4192 datasheet shows that from 22.05kHz to 96kHz the best fs setting is 256, however for 192kHz it shows 128fs is required and no other fs is supported. We have to use the chip in hw mode so I want to set it once and forget it, is it possible to set the MCLK to 128fs and output all frequencies? The PCM1681 (the other chip on the design) can support all sampling rates via 128fs.

Any help is appreciated!

over 9 years ago

0 Luis Fernando Rodriguez S. over 9 years ago

TI__Guru* 84915 points

Hi, Ekin,

The MCLK only can be configured as 128 * fs to use 176.4KHz and 192KHz. Please take a look at the TABLE I (Master clock frequencies for common sampling rates) for details ( www.ti.com/.../dit4192.pdf ).

Best regards,
Luis Fernando Rodríguez S.

0 EKiN BiNAL over 9 years ago in reply to Luis Fernando Rodriguez S.

Prodigy 120 points

Thanks Luis - this is what I saw in the datasheet as well. But what doesn't make sense is that the PCM1681 (www.ti.com/.../pcm1681.pdf) page 15 shows that 128fs can work with all sampling rates, why the limitation with the DIT4192? And what would you recommend for a workaround?

0 Luis Fernando Rodriguez S. over 9 years ago in reply to EKiN BiNAL

TI__Guru* 84915 points

Hi, Ekin,

Unfortunately, the DIT4192 has a different behavior and the available sampling rates are limited to the master clock frequency. In this case, the only solution would be modify the CLK0 level in hardware mode. CLK1 can be left at '0' and CLK0 could be used to modify the master clock frequency. CLK0 = '0' for 128*fs and CLK0 = '1' for 256*fs.

Best regards,
Luis Fernando Rodríguez S.

0 EKiN BiNAL over 9 years ago in reply to Luis Fernando Rodriguez S.

Prodigy 120 points

Understood Luis - I'll find a way to toggle that line for 128fs, thanks for the help.

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DIT4192 128fs support