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TPA2028D1: how to I control TPA2028D1 volume control??

taehwan lee
Prodigy 80 points
Part Number: TPA2028D1

Hello I am Luis

Let me ask a question.

I have a question TPA2028D1 volume control

[test circuit]

input 1kHz sinewave to IN+, IN- and attach RC filter(R-1kohm,  -4.7nF) to OUT+, OUT - 

and input signal 1kHz sinewave and output is also 1kHz sinewave.

[test result] 

i tried to change fixed gain value and test 

but all output is always same.

does not fixed gain value affect output sinewave voltage level ??

how can I change output sinewave voltage level??

CH1: 1Vpp, 1kHz sinewave)
M(output): CH2 - CH 3
CH2: AMP  OUT+
CH3: AMP OUT-

  • 0
    TI__Guru** 102045 points

    Hi Luis,

    TPA2028D1 has some audio processing features such as limiter and compression, perhaps the signal is limited by these features such that the change in gain is not affecting the output signal? You may try a couple things:

    • You can test by using a lower input signal amplitude until you see a change at the output signal amplitude as well, then reduce input signal a bit further and change the gain, you may now see some effect due to the gain as the signal would be below the set limit.
    • You can disable pretty much all the features in the device:
      • Set compression to 1:1
      • Disable output limiter using bit 7 from register 6.

    Best regards,
    -Ivan Salazar
    Applications Engineer

  • +1 in reply to Ivan Salazar
    Prodigy 80 points

    OK. It's my fault. This issue has cleared