TPA3140D2 - AGL function

Hirotaka Matsumoto

Guru 27565 points

Other Parts Discussed in Thread: TPA3140D2PWPEVM, TPA3140D2

Hi all,

Would you mind if we ask TPA3140D2PWPEVM?

TPA3140D2PWPEVM's settings are followings;

-J10 : Open(Adjustment with R7(LIMTHRES))

-J8 : 32dB(Any XXdB setting, it occurs noise. )

-J9 : SLOW(FAST/NOMINAL setting, it occurs noise.)

-Power : DC13V max 5A
-Speker : 4ohm streo

-Input：1.5kHz sinwave(Any setting of XXkHz, it occurs noise.)

We have question about AGL function.
When the AGL function operates, we guess that the AGL fuction confirm the input level and adjust the gain level.

And then, it occurs noise.
So, when we use AGL function, is it common to occur noise?

Kind regards,

Hirotaka Matsumoto

over 8 years ago

0 Don Dapkus over 8 years ago

TI__Guru**** 189399 points

Hi, Matsumoto-san,

There should be no noise. Can you send us scope shots of the output waveform?

-d2

0 Hirotaka Matsumoto over 8 years ago in reply to Don Dapkus

Guru 27565 points

Don san,

Thank you for your reply always.
We we get it from the cutomer ASAP, and then we will send it.

Kind regards,

Hirotaka Matsumoto

0 Hirotaka Matsumoto over 8 years ago in reply to Hirotaka Matsumoto

Guru 27565 points

Don san,

We attached the following file.
And then, R7 volume is the approx half.
20160205_TPA3140-D2.pdf

Kind regards,

Hirotaka Matsumoto

0 Peter Cao over 8 years ago in reply to Hirotaka Matsumoto

TI__Expert 5000 points

Hi, Matsumoto-san
From the waveform in the following file, we can't judge if it has noise in the waveform. Can this noise can be audible? What's limit threshold value customer set?

0 Peter Cao over 8 years ago in reply to Peter Cao

TI__Expert 5000 points

Hi, Matsumoto-san
It should be no noise with AGL function, so can you simple describe the noise with some text description.

0 Hirotaka Matsumoto over 8 years ago in reply to Peter Cao

Guru 27565 points

Peter san

It is difficult to describe the noise with some text description.
We would like to send the move file.
Could you let us know your E-mail address?

Kind regards,

Hirotaka Matsumoto

0 Hirotaka Matsumoto over 8 years ago in reply to Hirotaka Matsumoto

Guru 27565 points

Peter san,

We appologize that we could find your E-mail addresss.
We would like to send the file, however this data is too big.
Now, we are checking the tool to send the file, so could you wait for our E-mail for a bit short time?

Kind regards,

Hirotaka Matsumoto

0 Peter Cao over 8 years ago in reply to Hirotaka Matsumoto

TI__Expert 5000 points

Hi, Matsumoto-san

TPA3140D2's AGL gain step is 0.5dB , if customer play a continuous sin-wave with a too high limit threshold ,it will cause the output near PVCC clipping. The purpose of AGL is non-clipping, so if the device detect any possible clipping, it will try to decrease the Gain (0.5dB step, we can see a little amplitude variation on the output wave), so an effect method is trying to set the limit threshold a little lower. For example, if the PVCC is 12V, maybe we can set the limit threshold to 2.6V (try to change this value around 2.55V~2.65V, and monitor the output, until the output is stable) .

If customer want see no variation when they play continuous sine wave, they can:

With the same limit threshold (means same output non-clipping output power), only increase the PVCC value a little.
Keep PVCC the same, only decrease the limit threshold a little lower.

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TPA3140D2 - AGL function