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TPA3131D2 master/slave mode selection

Antony Lin
Genius 13480 points


Hi,

I see we have master/slave mode selectionn for the capability to synchronize with other devices.  I don't fully understand it.  What does it mean to sync with other devices? 

What if we don't need to sync to other devices?  How to connect SYNC pins and configure GAIN/SLV pin?

Besides, how should we configure AMx pins to reduce AM radio interference?  Based on table 6 iin datasheet as below?  What if the user will use the product under different AM frequency zones?

THanks!

Antony

  • 0
    TI__Genius 9175 points
    Hi Antony,

    The master vs slave mode determines the directionality of the clocking on the sync pin. For example, if the device is in master mode, no external clocking is necessary and the amplifier self generates a 100KHz clock frequency available on the sync pin that can be used to synchronize other devices in the system.

    In salve mode, the amplifier will not work unless 100KHz clock is connected to the sync pin as this is now an input to the amplifier.
    A key use case of this is for using multiple TPA3131 amplifiers on a system. One amplifier can be setup as a master and the other amplifiers as a slave with the sync pins connected together. Therefore the master will provide the necessary 100KHz clock to the other slave amplifier’s clocks and PWM signals are synchronized.

    Table 1 on page 12 of the datasheet shows the correct resistors to use to set the desired gain as well as master/salve mode of the device. If you are using just one TPA3131 than most likely you would set the device up as a Master and leave the sync pin floating.

    The AM pins are used to change the switching frequency of the amplifier to shift the EMI spectrum. This requires testing in an EMI chamber with the end equipment to see if a different switching frequencies will reduce EMI in a problematic band.

    Regards,
    Matt