DIY DAC PCM1796 : Sampling frequency

[G Netix]

Hi,
I plane to build a DAC for monitoring, and I chose PCM2707 & PCM1796.
I think I've understood the whole fonctionality of each device, except two points :

First in PCM1796's datasheet, they talk about "Sampling frequency" and "Over-sampling Frequency". what's the difference?

Second point : The system frequency SCK of PCM1796 comes from "FUNC2" generated by PCM2707. But I would like to be able to change the sampling frequency from 44.1kHz to 192kHz only using SPI commands. Is it possible to connecte SCK pin to another clock than PCM2707's one? perhaps an external programmable oscillator?

thank you!

[Ken Newton]

Originally Posted by G Netix

Hi,
I plane to build a DAC for monitoring, and I chose PCM2707 & PCM1796.
I think I've understood the whole fonctionality of each device, except two points :
First in PCM1796's datasheet, they talk about "Sampling frequency" and "Over-sampling Frequency". what's the difference?

The "sampling frequency" is probably meant as the input sample rate to the digital interpolation filter - which means to the PCM1796 since it has the DF integrated on chip. The "oversampling frequency" is the sample rate coming out of the digital interpolation filter, and will be some base 2 integer multiple of the input rate (such as x4, x8, x16) unless asynchcronous upsampling is being utilized instead of simple oversampling.