AnsweredAssumed Answered

ADAU1701 MCLK frequency switching

Question asked by neb on Jun 14, 2017
Latest reply on Jun 14, 2017 by DaveThib

I currently have USB to I2S card running in UAC2 mode (Audio Widget project) which is feeding ADAU1701 with I2S signal with MCLK which is being switched between 24.576MHz and 22.5792MHz depending on the sample rate of the source audio signal. It all works fine up until 24bit/192KHz material except for one thing - there is an audible pop when f is being switched from one value to another. I'm just wondering if there is a way out of this? Is switching necessary or can ADAU1701 derive necessary f from single frequency, one of the two, to avoid switching?

 

PLLMode0/1 are both pulled high, and DSP core program length is set to 4x256 per this article:

Setting the PLL mode for the ADAU1701 at different sample rates 

 

Another question: is there an easy way to increase output level on the analog DAC outputs 0-3?

Outcomes