TAS5805M: Thermal Question

Hideki Hayashi1

Part Number: TAS5805M

Hi team,

I would like your help to answer below question.

1. Jucntion temp calculation

Users wants to calulate junction temp for local standards. If customer measure the case top temprature, Tj will be calculated as Tj = Tc + (ψJT * Power), correct?

They are measureing the temprature at TC1 of the picture

In addition, how to calcurate Power in such a class D amp IC?

2. The way to reduce Tj

Users wants to have lower temprature in the system.

With PVDD = 12.6V, Fs = 384kHz, currently TC1 is 105℃

Could you suggest any way to reduce power consumption?

Regards,

Hideki

over 4 years ago

+1 Shadow He over 4 years ago

TI__Guru 52460 points

Hi Hideki

1. Your calculation is right. You can calculate the power dissipation in our AMP by Efficiency curve in our Datasheet.

IC power dissipation = output power / Efficiency - output power

2. With lower PVDD voltage, use 1SPW mode, can have higher efficiency, thus reduce the temperature.

Optimize PCB to conduct thermal flow. Use larger copper area and more via under the IC.

0 Hideki Hayashi1 over 4 years ago in reply to Shadow He

TI__Expert 8820 points

Hi Shadow,

Thanks for comments. Can you please let me know where the attached picture is?

Regards, Hideki

0 Dylan Yao over 4 years ago in reply to Hideki Hayashi1

TI__Genius 11090 points

Hideki,

It is public holiday in China. Shadow will be able to feedback you tomorrow

Dylan

0 Shadow He over 4 years ago in reply to Hideki Hayashi1

TI__Guru 52460 points

Hi Hideki

It's one of our training PPT, I'll send you through e-mail.

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TAS5805M: Thermal Question