ADAU1777 AEC with DSP


we are currently redesigning our voice control unit and for that we need a IC that can transform a mic signal and use it with a digital audio signal to do AEC filtering. I've noticed the integrated DSP part in the ADAU1777 and came across some documentation on AEC filter design with sigma studio. Before ordering dev-boards, i wanted to make sure if understood these possibilities right. Am i able to configure the DSP of the ADAU this way or do you have a better solution for these circumstances. The modified output-signal should then be used via DAC and the mic signal should be forwarded digitally for further bluetooth usage.

Best regards and thanks in advance!

  • 0
    •  Analog Employees 
    on Jul 23, 2021 1:29 PM

    Hello MAJMAX,

    The DSP in this part is called a "fast DSP" and it is really just a filter engine that performs 32 Biquad filters very quickly. It was developed to do ANC applications. ( Active Noise Cancellation ) AEC is a little different. I am not expert in the AEC algorithms so I am not 100% certain this will serve your purposes. We have another part, the ADAU1787 that has two DSP cores. It has a fast core that can perform 64 BiQuads per sample period and the second DSP core is a SigmaDSP core that runs slower but can be used to adjust the filtering to adapt to changes by using feedback and changing the coefficients in the fast DSP. 

    Both of these parts have sample rate converters, ( ASRC) that are connected to the serial data ports so that a Bluetooth part can send it clocks and get data at a slower rate. The ADAU1787 has two serial ports. Both parts have the ability to choose what is sent to the serial port so you can send the raw ADC data or post DSP etc. 

    The ADAU1787 runs on a 1.8V max power supply where the ADAU1777 can run up to 3.3V. 

    You say you are redesigning a voice control unit. Do you need to do any voice control processing with this device or is this only for voice pre-processing before decoding the speech? We have the ADAU1472 that is built for voice control processing. 

    Then for AEC we have some IP that runs on the ADAU1467 and ADAU1452 platforms. 

    Dave T