Op amps in the aux interface of speakers

Wesley Huang

Expert 1030 points

Hi team，

Do you have any reference design about amplifier which is used in the AUX IN of the Bluetooth speaker for the Single signal and differential signal conversion ?
As far as you know, what role do op amps usually play in the aux interface of speakers?

Could you please share with me?

Best Regards

Zhihong Huang

over 4 years ago

0 Luis Fernando Rodriguez S. over 4 years ago

TI__Guru* 84915 points

Hi, Wesley,

Our team will take a look at this thread and will answer as soon as possible.

Best regards,
Luis Fernando Rodríguez S.

0 Wesley Huang over 4 years ago in reply to Luis Fernando Rodriguez S.

Expert 1030 points

Hi team，

Thanks for your reply, please answer my question as soon as possible.

Best Regards

Zhihong Huang

0 Ivan Salazar over 4 years ago in reply to Wesley Huang

TI__Guru** 102275 points

Hi Zhihong,

Perhaps you're referring to a Line Receiver?

Usually AUX inputs/outputs use Line Drivers/Receivers. The output of the Line Receiver can then be connected to a power amplifier.
Here you can check our Line Receiver Portfolio: https://www.ti.com/audio-ic/amplifiers/line-receivers/products.html

You could also use an op amp, based on your requirements for supply (dual, single, voltage level), noise, gain, differential or single-ended, etc.: https://www.ti.com/amplifier-circuit/op-amps/audio/overview.html

The op amp or line receiver connected at the AUX input is used for impedance coupling purposes, ground loop noise improvement as well as preamplifier for the power stage.

Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuators

0 Wesley Huang over 4 years ago in reply to Ivan Salazar

Expert 1030 points

Hi team，

Thanks for your reply.

1. Do you have any reference design via line driver or op amps used in the AUX IN of the speaker or mixer?

2. what's the difference between the line driver and op amps for the AUX IN of the speaker or mixer?

Best Regards

Zhihong Huang

0 Ivan Salazar over 4 years ago in reply to Wesley Huang

TI__Guru** 102275 points

Hi Zhihong,

I'm not aware of a reference design specifically for AUX Input applications. Line drivers and receivers are a specific kind of op amps, as you can read in the description of our Line Receiver devices:

Differential-input amplifiers integrated with high-performance op amps and precision well-matched thin-film resistors, delivering great noise immunity

Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuators

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Op amps in the aux interface of speakers