LM48560TLEVAL: Analog Audio Amplifier Output Trace PCB layout

Ena Peh

Part Number: LM48560TLEVAL
Other Parts Discussed in Thread: LM48560,

Tool/software:

Hi TI Experts,

I am new to PCB layouts and I am current reviewing the LM48560 and its evaluation board for reference. In the datasheet, I noticed a layout guideline recommending the use of wide traces for the amplifier outputs, as shown in the attached image.

My question is: what is the typical trace width for audio amplifier outputs? Would a 20 mil width be sufficient, or what size would you suggest the trace width to be in mils?

Actually, can I consider using the 100-ohm differential impedance matching for audio analog signals approach for this IC instead?

Additionally, I tested the evaluation board LM48560TLEVAL and observed a current draw of 400mA from the power supply at max gain. Hope the information provided is enough for your inputs to my questions.

Thank you for your help!

Best Regards

Ena

1 month ago

0 Ena Peh 1 month ago

Prodigy 220 points

Sorry, the alternative approach I was referring to is the controlled impedance approach

+1 Ivan Salazar 1 month ago in reply to Ena Peh

TI__Guru** 110615 points

The basic requirement is that output traces does not represent a higher or same load as the speaker.

Impedance matching is not so much of a concern for audio content, the frequency range is only up to 20kHz. Unless the output traces are way too different from each other, for most cases the mismatch between output traces is negligible.

Best regards,
-Ivan Salazar
Applications Engineer

0 Ena Peh 28 days ago in reply to Ivan Salazar

Prodigy 220 points

Can I say around 20 mils trace width is wide enough for audio output traces?

Best Regards,

Ena

0 Sydney Northcutt 27 days ago in reply to Ena Peh

TI__Mastermind 19480 points

Hi Ena,

Yes 20 mils trace width is okay.

Regards,
Sydney Northcutt

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LM48560TLEVAL: Analog Audio Amplifier Output Trace PCB layout