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LM48901

tirthraj chandake
Prodigy 60 points

Other Parts Discussed in Thread: USB2ANY

Hi

Can you please review attached schematic for LM48901LLP. My requirement is only analog audio input so I removed SPDIF source and redesigned board. Also designed for 4-speaker to 16-speaker configurable (Master-Slave). Please suggest any correction needed.

I have few question please clarify.
1. What is the use of EEPROM (AT24C512) in reference design. It is always disconnected by jumper.
2. Any option to AARDVARK USB-I2C device? Can there any alternate option to Load Coefficients?
3. Any special requirements for power supply. Can we use SMPS based power input? will it effect quality?
4. If we design PCB with 2 layer can quality affect?

5141.LM48901LLP_Schematic.pdf


Thanks & Regards,
Tirthraj

  • 0
    TI__Expert 3350 points

    Tirthraj,

    1. The EEPROM is there so that the EVM user can load coefficeints and device setups into the 901 without needing to connect to a PC.

    2. The GUI was designed for either the Aardvark or TI's USB2ANY USB to I2C interface.  If you are not using the GUI and have a different I2C controller, just connect the SDA, SCL and GND lines to the jumper.

    3. The 901 works fine with SMPS power supplies.  As with any audio design, make sure the supply is well bypassed and regulated.  More importantly, make sure the supply has more than enough current headroom.  The 901 will make very unappetizing screeching sounds if the supply collapses due to current limitations.

    4. As long as you can provide good ground and supply routing, while keeping the inputs away from noise sources.

    Schematic:

    The I2C_EN connection on the daisy chain output connector should actually be I2C_EX.  I2C_EX is the output of the preceding device that drives the I2C_EN of the following device, once the preceding device is completely configured. 

    Regards,

    royce

     

  • 0 in reply to Royce Higashi
    Prodigy 60 points

    Thanks Royce,

    As per my understanding

    1.  If I download coefficeints generated from web tool directly to EEPROM and I connect SDA, SCL and GND to LM48901 then it works.

    2.  I can download coefficeints in EEPROM using any generic USB-I2C adapter or through microcontroller.

    3.  LM48901 read data from EEPROM on "POWER ON"

    4. GUI is only required for debug, equalizer and some extra optional settings.

    Please correct my understanding if any.

    Please provide information of "TI's USB2ANY USB to I2C interface" product. link from TI site and purchase information.


    Thank you very much for quick support.


    Thanks & Regards,

    Tirthraj



  • 0 in reply to tirthraj chandake
    TI__Expert 3350 points

    Trithraj,

    While you can program the EEPROM independently, I would suggest using the LM48901 to write to the EEPROM.  That way the device writes the configuration and coefficient data to the proper memory addresses in the EEPROM.  Use the GUI to program the 48901 with the coefficients ahd the desired configuration settings, then go to the EEPROM tab, select the device and click on the Write to eeprom button. This will cause the LM48901 to dump all its register contents to the EEPROM.  Once that is complete, any time you power up the device, it will automatically read from the EEPROM.  Make sure you use the latest version of the GUI (3.7.0.0) available at TI.com.

    I'm looking for any documentation on the USB2ANY.  I would suggest getting in touch with your TI sales rep for ordering information.  The USB2Any serves as a replacement for the Aardvark, so if you have an Aardvark, you don't need the USB2ANY at this time.

    Regards,

    royce

  • 0 in reply to Royce Higashi
    Prodigy 60 points

    Thanks Royce,

    I dont have Aardvark tool.

    Is the following tool same you are talking about USB-ANY (http://www.ti.com/tool/usb-to-gpio). if other than this then please provide information.

    In the web tool  of Spatial Audio Speaker Designer help I found "Range of input" that is  

    distance from the listener to the origin should be within 40 and
    100cm. Error message will prompt if user inputs are out of range. 

    but in it gives error massage after 500cm. so which one is correct.

    Thanks & Regards,

    Tirthraj


  • 0 in reply to tirthraj chandake
    TI__Expert 3350 points

    Tirthraj,

    The USB2ANY is only available with our EVMs.  If you order a LM48901 EVM, you will also receive a USB2ANY.  Aardvarks are available for purchase direct from Total Phase.

    The spatial effect works best when the listener is between 40-100cm away.  But the design tool will allow you to create coefficients for up 500cm distances. 

    REgards,

    royce