TPS65218D0: TPS65218D0PHPT DCDC4 Startup

Please share your schematic so we can verify the design.

Dear, Brian.
The schematic diagram should be no problem. I doubt that TPS65218D0 has not completely solved the similar problems existing in TPS65218B0.
Thanks & Best Regrads,
Alex

Alex,

Can you please provide a scope shot showing that LDO1 turns on correctly, DCDC3 turns on correctly, then DCDC4 fails to turn on?

You can also monitor DCDC1 or PGOOD to show that DCDC4 is the reason the PMIC fails to finish the power-on sequence.

Hi, Brian
I replaced three TPS65218 chips already solved this problem. The problem is that the TPS65218 startup is not stable. My concern is that this problem will persist after the mass production of our products.

Thanks & Best Regards,
Alex

Alex,

Please provide scope shots of the issue occurring so we can continue to debug your problem.

Note there may be a delay in responses until after Jan. 2nd due to US Holidays.

Hi, Brian
For the following reasons, the scope shots are not available at present.
1\ At present, only one PCB board has been produced.
2\ The problem has solved by replacing the chip TPS65218D0.
3\ Now the main problem is to worry about the inherent problems of chip TPS65218D0 the same to chip TPS65218B1 , which will affect the subsequent mass production of our product.

Happy holidays!
Thanks & Best Regards,
Alex

Alex,

I understand your concern, but as of now we have not had any quality issues with the TPS65218D0 silicon (PHP or RSL package).

We cannot confirm there are any issues with the TPS65218D0 silicon without debugging the issue and understanding the root cause. Please provide more details and scope shots when they are available.

Hi, Brian
Yesterday, we had a test with Mr. John Xu of TI. The test waveforms and replacement position you need was tested. Mr. John Xu will send you an email about detailed test instructions. Thank you very much.


Thanks & Best Regards,
Alex