TPA3255: problems with using

user5930653

Part Number: TPA3255

Good day. I am designing a power amplifier based on TPA3255.
The following issues occurred:
The voltage at pin 11 varies in the range of 2.5-3.3 volts.
With the increase of the signal level in the speaker system there is a crack. The power supply voltage is currently 24 volts. Distortions are visible in the photo, with about 6 dB remaining before clipping.

The wiring diagram is fully consistent with the documentation on the chip.

over 6 years ago

0 Dylan Yao over 6 years ago

TI__Genius 11080 points

Hello,

Pin 11 should be consistent 3.3V, it is abnormal that varies between 2.5V to 3.3V. can you do below:
1. capture the DVDD pin waveform?
2. capture the waveform of pin 19, 21 to see if any fault reported.
3. capture waveform of GVDD to see if there is any abnormal.

Dylan

0 Dylan Yao over 6 years ago in reply to Dylan Yao

TI__Genius 11080 points

Also, if schematic and layout of the AMP part can be showed, that would help us analysis.

0 user5930653 over 6 years ago in reply to Dylan Yao

Prodigy 40 points

Good day. The last thing I did, increased the power on the legs of the PVDD to 38 volts. A 1 kHz sinusoidal signal was applied to the input of the AB, and a 4 Ohm resistor was connected to the output. With an amplitude of 12 volts at the output, the chip turned off the output, the resistor in the GVDD_CD circuit (3.3 ohms) began to smoke, and the chip then burned. Now I plan to redo the board and try again.I think the problems in the layout.

Архив WinRAR.rar

0 Dylan Yao over 6 years ago in reply to user5930653

TI__Genius 11080 points

I can't open the lay6 format file, as i only have AD and Allegro available, can you post a pdf format file.
I would suggest to find the root cause before re-do the board...

0 user5930653 over 6 years ago in reply to Dylan Yao

Prodigy 40 points

In the archive program to open these files, it is better to see it there than in pdf.

2538.Архив WinRAR.rar

0 Dylan Yao over 6 years ago in reply to user5930653

TI__Genius 11080 points

Sorry, i still have problem to use this software. below is the screen capture, language is not correct, i can't use it. Is there english version software? Is it free software or need a license to use? If need license, i prefer to use pdf forma file.

to improve commnucation efficiency, shall we discuss with email? May you send email to me dylan-yao@ti.com

0 user5930653 over 6 years ago in reply to Dylan Yao

Prodigy 40 points

Made new board. Problems remained.

0 Dylan Yao over 6 years ago in reply to user5930653

TI__Genius 11080 points

Hello,

May you start a new thread, and post the pdf format schematic and layout(each layers), so we can take a deep look. And please probe the waveform of OUT pin and fault pin, under small amplitude input(just to avoid burn).

Start a new thread will just makes our life easy. Thanks your help.

Dylan

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TPA3255: problems with using