WEBENCH® Tools/TPA3220: How to choose the low-pass filter inductor for the TPA3220 Class D power amplifier output?

user5005898

Part Number: TPA3220

Tool/software: WEBENCH® Design Tools

Excuse me, how do you choose the TPA3220 Class D power amplifier output low-pass filter inductor?
The TPA3220 EVM recommends a large inductor size. I want to know how to design or how to use the inductor specifications IDC and ISAT when I want to apply it to a mono 60W speaker.

over 5 years ago

0 user5005898 over 5 years ago

Prodigy 120 points

Supplementary explanation:
The input voltage for this case is 12v

0 Shawn Zheng over 5 years ago in reply to user5005898

TI__Mastermind 24835 points

Hello,
We a document that introduces the LC filter design for class-d audio amplifier. www.ti.com/.../slaa701a.pdf
www.ti.com/.../slac729
Best regards,
Shawn Zheng

0 Robert Clifton56 over 5 years ago in reply to Shawn Zheng

TI__Mastermind 20830 points

Hi user5005898,

To add to Shawn's answer, as you mentioned the IDC and ISAT are important characteristics when choosing an inductor for the LC filter. Make sure to calculate the maximum expected current draw you expect to come out of the amplifier and choose an inductor that can handle at least a few amps more than the expected max to be safe. I would also recommend choosing an inductor who's inductance is still in the "flat" portion of the Inductor vs Current, since you don't want the value to change greatly depending on how much current is going through your LC filter.

I hope this helps!

Best Regards,

Robert Clifton

Audio

Audio forum

WEBENCH® Tools/TPA3220: How to choose the low-pass filter inductor for the TPA3220 Class D power amplifier output?