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ADAU1442 with Two ADAU1701



I am making a prototype for which my requirement is as given below:


1. SPDIF Input (1)


2. SPDIF Output (1)


3. Analog Input (at least 1 stereo channel)


4. Analog Output (at least 3 stereo channels)


For the above requirement, I think the least complex (cost-wise, component count wise) way is to use ADAU1442 with two ADAU1701/02.


Kindly guide me on my design thoughts below:


1. Use only one 12.288MHz crystal connected to ADAU1442 and use its MCLKO to drive the ADAU1701/2.


2. Use all three chips in selfboot  mode with their own EEPROMS. The contents of the two ADAU1701/2 may or may not be the same.


3. Set ADAU1442 address to 00 with its EEPROM address lines also set to 000


4. Set ADAU1701/2 to two different addresses 00, 01, 10 or 11 by using ADDR0 and ADDR1 lines. Say, 00 and 01.


5. Route the 2 x ADAU1701/2 ADC inputs to ADAU1442 for processing effectively using it only as a 2In, 4Out CODEC.


6. Route all the processed channels to the DACs of ADAU1701/2, effectively using it as a audio processor with SPDIF IN/OUT and SERIAL IN/OUT.


My doubts are as below:


1. For the ADAU1442:
  a. What should be the PLL0, PLL1 and PLL2 lines be set to?
  b. What should the CLKMODE0 and CLKMODE1 lines be set to?
  c. Will ADAU1446 also suffice in my case?


2. For the two ADAU1701/2:
  a. What should be the PLL0 and PLL1 lines be set to?
  b. What should be the EEPROM address lines be set to? I do not want to overwrite the SigmaStudio programmer EEPROM.


Any thoughts suggestions or corrections will be of much help to me.
DO let me know if you need any further details for better clarity.


Thanks in advance!



  • Hello KKSL,

    Are you starting this design from scratch and developing schematics, or working with available off-the-shelf options (ADAU1701s and ADAU1442)?

    For the price of an ADAU1442, you can instead consider the ADAU1451, which has 8K instructions, and 16Kdata memory (twice the memory of the ADAU1442) and has the SPDIF Input/Output.    I would assume this would be less board space and power?

    Perhaps you can consider the AD1938 codec (roughly less than the cost of 2 ADAU1701s), but if that is too much cost, you can consider any available commercially available 2-ch in x 4 -ch out codec.   The AD1838 is the codec used on the ADAU1452-MINIZ eval board will be sufficient for your application as the board has 4 inputs and 8 outputs and the ADAU145x also provides the ability to self boot like the other SigmaDSP parts you are considering.   The clocking scheme should be simple, you can set the ADAU1451 as the serial bus master for the codec and provide it's CLKOUT to the codec's MCLK pin.


  • Hello John,

    Thank-you for your early reply.

    I did consider the ADAU1451 and the AD1938 CODEC.

    The ADAU1451 is a new part and the algorithm libraries are not completely available/ported yet. If AD updates the SigmaStudio libraries soon, the AD145x can make its way in. I am designing from scratch and the schematics will not freeze in another 10 days.

    The AD1938 CODEC is nice, but it is costly. Moreover, it needs at least 8 low noise dual op-amps and the associated precision components for the ADC and DAC filters further adding to the cost and the real estate.

    Spec-wise, the AD1938 will measure better. However, sonically, will it be better?

    One elegant option is ADAV4601 which will need SPDIF Transceiver like WM8805, but it only gives me one stereo analog input.

    This one requires some additional micro controller based development, but it will only be a one time effort. If the requirement of two stereo analog inputs relaxes, this option could surge ahead.

  • Hello KKSL,

    Have you looked at the latest 3.12 beta release?  Can you comment on which algorithms you are looking to use that are not included.   I can understand if you are looking for some of the older 3rd party algorithms which might take a while, but most of the common dynamics processors and filters are included.  3.11.2 added AVC, peak and multi-tap compressors for the ADAU1452.   In addition, on the ADAU145x you can do some block processing and multi-rate filtering as well.

    On second look, I think your use of the 2 ADAU1701s for the 3 stereo outputs is very comparable to an AD1838/ADAU1451 option, as you get the 100 MIPS performance with the two ADAU1701s and combined you will have similar performance of a single ADAU1451.   The power consumption of an ADAU1451 is similar to an ADAU1442, and the power consumption of 2 ADAU1701s (573 mA) is slightly higher than a single AD1938 (429 mW typical).     Although, you can save on the cost of 2 additional serial EEPROMs with the AD1938 option, but as you say, you need more external analog components to support that product.

    I will take a look at your ADAU1442/ADAU1701 design questions and follow up later on those.


  • Hello John,

    I am looking for Basic DSP, Dynamics Processors and ADI Algorithms (AVC, Midnight Mode, Virtual, Surround, Loudness, Dynamic Bass, LF Synth, etc.) for the ADAU145x. I am sorry, I only had v3.11.1 loaded.

    Could you kindly link me to the latest version? The download page shows v3.11.1 as latest beta.

    Thanks again and regards!!

  • Hello John,

    Chances are that this will catch you in your early Christmas vacation. If not, here is an update from my side:

    I have decided to opt for the ADAV4601 as I could relax the sepc on analog inputs to one stereo.

    I'll use WM8805, in HW mode, for SPDIF In/Out. It is not costly at all.

    The ADAV4601 System document talks about Application Layer Software GUI for custom flow.

    Kindly let me know where to find this. If you are on vacation, hopefully, someone else from AD will jump in before they take off for Holidays.


  • Hello Karagir,

    You just caught me, my Christmas vacation starts later this week.

    The ADAV4601 looks like a good option.  I am not too familiar with this part as it was developed by a different group, but looking at the datasheet it looks like an ADAU1701 with integrated SPDIF and ASRCs and has the same I2C register command protocol as other SigmaDSPs.

    I am not familiar with the System document which you refer to.   I assume this is not the ADAV4601 datasheet?  The datasheet mentions to use the SIgmaStudio tools for GUI development, and looking at SigmaStudio I do see this audio processor is supported.   However, it looks like the on-chip registers are programmed with some sort of script instead of the usual graphical register view we provide.

    I will try to find out more details from others who are familiar with the product and try to get you more details.


  • Hello John,

    The system document and the schematic for the now obsolete eval board for the ADAV4601 are in the wiki link (Tutorials [Analog Devices Wiki]) wiki/sigmastudio tutorials under the ADAV4601 Evaluation board heading.

    BretG (Is he not in AD anymore?) put it there in connection to one of my previous posts (

    John, before you leave for holidays, could you kindly share the link for the latest version of the Application Layer Software GUI?

    Could you also connect me to the Ireland team that supports this chip? That way, I could use a lot of last half of December time for my development.

    Thanks in advance and warm regards!!

  • Hello John,

    Is there any chance that you could link me with the Ireland Devlopment Team and/or the Application Layer Software GUI (For the ADAV4601) before you leave for Christmas?

    Thanks in advance and regards!!

  • Hi Karagir,

    I have put in a request for information beyond what is available on the Wiki. If I hear anything, I will post it immediately.

    Best regards,


  • Super!

    Thank-you sir to you and your team.

    I'll check the forum regularly.

    You have a great week-end and Merry Christmas to you all, in advance!!