AD1934 interface with Microcontroller - Not able to hear anything on DAC output

Hi,

I'm interfacing the AD1934 DAC to an MCU's SPI interface. I have connected a 12.288MHz external clock signal to the MCLKI pin and left MCLKO pin as open.

Following are the AD1934's register configuration.

DAC Control 1 --> 0x60

DAC Control 2 --> 0x18

PLL and Clock Control 0 --> 0x98

DAC individual channel mutes --> 0x00

I have read back the registers what i have written and its the same what i have transferred.

I have also probed the LR Clock, Data and Bit clock lines and everything seems to be fine. But I cannot hear anything on the DAC output.

The audio data is a 16-bit signed LE with 48kHz sample rate. I have extracted the samples from .wav file and stored it in a C array format using a python script and used it in my code.

In some other post I've read that the data size is always 32-bit for AD1934. I have configured my master accordingly but no audio is coming out.

My MCU master uses the bit clock from AD1934 and generates the LR clock and data to be input to the AD1934.

Am i missing anything?

BR,

Tri

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    •  Analog Employees 
    on Apr 10, 2020 5:03 PM 9 months ago in reply to memo

    Hello memo,

    Can you show us your schematic? For the PLL to lock you need to have a valid master clock or the registers set to route the LRCLK to the PLL input. Then you need the correct PLL filter. Then all the correct power and ground. I have seen poor PCB layouts cause issues with the PLL not locking. So the details are with what you are doing and how your PCB was implemented. The only way to help you is to have more information on your specific system details. 

    Dave T

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