TAS2560: PDM Interface not used and connected

Hi Jakob,

First of all let me comment you could take a look at TAS2562. This is update from TAS2560 with higher internal boost range, useful in case you need higher power at the speaker.

Regarding PDMCK and DOUT pins, it is OK to leave these pins floating, no problem.

Please let us know what is the MCLK, WCLK and BCLK frequencies you're expecting to use, as well as data format. I can support testing on my side and providing some script and instructions around it.

Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuators

Hi Ivan,

thank you for your suggestion, for now we will continue with the TAS2560.

I was planning with an audio sampling frequency of 44 kHz, 24 bits on 32 bits frame. So I assume the following frequencies:

WCLK = 44 kHz

BCLK = 2,82 MHz

The outputable I2S MCLK from the MCU is 72 MHz, which is above the 49,15 MHz max. MCLK input. Instructions and best practices on hte frequencies would be helpful!

Best regards

Jakob

Hi Ivan,

I had I deeper lock into the clocks. I can now be a bit more precise:

MCLK: 72 MHz

Fs: 44,1 kHz

Data: 24 Bit

Frame: 32 Bit

Channel: 2 (L/R)

-> BCLK: 2,82 MHz

->WCLK: 44,1 kHz

Since MCLK is too fast (72 MHz > 20 MHz), I was going to use BCLK (2,82 MHz) as PLL input. With P = 1, J = 16, D = 0 -> PLL_CLK = 45,1585 kHz

This should be fine, because they meet following two criteria:

PLL_CLK = 45,1585 kHz = Fs * 1024 = 44,1 kHz * 1024

512 kHz < PLL_CLK/2^p = 1,4112 MHz < 20 MHz

The TAS2560 will be configured in Mode 3 with PDMCK and DOUT left floating. MCLKL is not needed, because the BCLK (2,82 MHz) input for PLL_CLK is above 1 MHz. So the MCLK pin will be left floating as well. Is that correct and good practice?

I will send on 2 Channels the L and R signal, Input Mixing for the mono output will be done by the TAS2560. Correct?