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TAS5822M: Open Load Detection

Part Number: TAS5822M

Hi team,

The figure above is a screenshot of the TAS5822M datasheet indicating that there are Open Load Detection and Short Load Detection features, but there are no corresponding load diagnostic registers in the datasheet. How do we use both features? How do we know the detect results?

Best Regards,

Amy Luo

  • Hi Amy

    let me confirm with our EVM board and reply you.

    jess

  • Hi Amy,

    Tested with our EVM found the device works normally in OL state, and reports OC faults in SL state.

    And sorry to tell you this device tas5822m doesn't have OL/SL error detection function, and we will change the description in the datasheet soon.

    Regards 

    Timi 

  • Hi Timi,

    Glad to see your reply.

    I know that the SL detect result can be obtained from the OC fault. But how do we know the OL detection status? 

    Best Regards,

    Amy

  • Hi Amy

        Sorry that this device can't detect the OL status. May I ask that does our customer need this OL/SL detect function? It's rarely seen on the consumer side products. 

  • Hi Shadow,

    Thanks for your response.

    The customer said they have an amplifier product on hand using the TAS5822M chip, its control software has a function option of load detection, each channel takes about 10s of test time, the end of the test will show the channel load open or short circuit condition. It is not clear how the product does this.

    Guess if the TAS5822M has some readable registers to read out the audio output level at which the software can determine an open or short circuit to a load?

    The 0x60 register and the 0x64 register under book-0x78, page-0x02, what do they do? Are the values of the two registers the size of the output level, and if so, how are the values converted to voltage?

    Best Regards,
    Amy 

  • Hi Amy 

        The output level register will reflect the output voltage level, no matter there's load or open load, the output voltage won't change, no way to detect OL.

        The control software for this device is only PPC3, I think we can't find anything about load diagnostic function. 

        I'm afraid our customer is a little confuse this device with our another device TAS6422, below picture from TAS6422 PPC3, the load diagnostic function, it's hard to miss if there is one. Could you please let our customer give a picture about it?

  • Hi Shadow,

    This control software is not PPC3.  I may not have clearly described the customer's issue. This customer has an audio power amplifier device. This device was not designed by them, maybe they bought it. The control software mentioned above is the control interface software for this device.

    Best Regards,
    Amy

  • Hi Amy

       In that case, I think in that device, there's some other circuit to detect open load, not by TAS5822 itself.

  • Hi Shadow,

    Thank you for your supports. The customer intends to switch to TAS6422.