PMP30720: Not powering ON

kirubakar Nagarajan

Part Number: PMP30720

Tool/software:

As per the Reference design files, we have assembled the new board for our testing. When 24V DC Input voltage is provided, the SMPS is tripping due to over current. We traced the new PCBA for any short circuit but there is no traces of short circuit. Could you please tell us what is initial current, the device will draw from SMPS. Also, in schematic, RT100 and RT101 value is mentioned as "TBD". Could you please suggest the suitable part to use in the design.

The Optional DC-DC disable circuit is not mounted as per schematic. The DNP components are considered as per schematic. But when I refer to TI Test Report document (file name: TIDT143) the below was found. In that Optional DC-DC disable section was assembled and also RT100 & RT101 was placed.

So, Please let us know whether we need to assemble optional DC_DC disable circuit or not. And kindly share the Manufacturer Part Number for RT100 & RT101.

Attached the newly assembled board for reference.

1 month ago

0 Florian Mueller31 1 month ago

TI__Prodigy 490 points

Hi, thanks for your message.

RT100 and RT101 is not required for startup, I tested it with shorting RT100. And you do not have to assemble the optional DC DC disable circuit. To figure out your problem I recommend to remove RT1, RF1. This will separate the boost stage from the Flyback. Therefore you can test the boost and the flyback separately. For testing the boost you could connect a load to TP1, TP2 (warning high voltage). For testing the flyback you could connect a DC supply to C2.

Thanks,

Florian

0 kirubakar Nagarajan 1 month ago in reply to Florian Mueller31

Prodigy 80 points

Thank You soo much for your feedback. Now the PCB is working. I just removed the over current protection setting in my RPS and after that the board is powering ON. I couldn't able to measure the inrush current. I feel like the starting current is more that's why the RPS is not allowing to power up when OCP is enabled. Do we have any article related to this design, how its working. I need to know the active flyback circuit section. How its working and functioning. Could you please through some light on this working?

0 Florian Mueller31 1 month ago in reply to kirubakar Nagarajan

TI__Prodigy 490 points

Good that the design works now.

There is a great topic regarding the active clamp flyback which desribes the basics:

https://www.ti.com/seclit/ml/slup380/slup380.pdf?ts=1725024260529&ref_url=https%253A%252F%252Fwww.ti.com%252Fdesign-resources%252Fseminars%252Fpower-supply-design-seminar-psds%252Fpsds-resources.html

You can download a video and a white paper as well. Just go to that link below and search for "Comparison of GaN- and silicon FET-based active clamp flyback converters"

https://www.ti.com/design-resources/seminars/power-supply-design-seminar-psds/psds-resources.html#2018

Thanks,

Florian

0 kirubakar Nagarajan 1 month ago in reply to Florian Mueller31

Prodigy 80 points

Hi Florian,

Thanks for the links...

I couldn't able to open the 1st link which you have provided above. And in second link, I couldn't able to download the whitepaper remaining two (presentation & video) I can able to view. Could you please do the needful.

Thanks,
Kirubakar

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PMP30720: Not powering ON