TPS62903: Inrush Current

Jonathan Tshimama-Kabangu

Part Number: TPS62903

Hello,

I'm trying to understand how much capacitance contributes to Inrush ,let's take a look of my circuit

Image 15-12-2025 at 23.50.jpeg

PWR_CVSYS_5V is the output from TPS62903 ,this IC has capacitors(C251,252,253,254,255)

also connected to this rail is:

Image 15-12-2025 at 23.51.jpeg

Image 15-12-2025 at 23.52 (1).jpeg

Image 15-12-2025 at 23.52.jpeg

Image 15-12-2025 at 23.51 (1).jpeg

Image 15-12-2025 at 23.51.jpeg

do all this capacitors add to the inrush or is there cut off point where it does not affect anymore

Regards

Jonathan Kabangu

0 Haseen Reddy Siripi Reddy 8 months ago

Hi Jonathan Kabangu,

Yes all these capacitors will cause the inrush.

However TPS62903 has soft start function and you can increase SS cap value so that the inrush current can come down.

Regards,

Haseen.

0 Jonathan Tshimama-Kabangu 8 months ago in reply to Haseen Reddy Siripi Reddy

Hi Haseen,

Thanks for the response,

one last question: does PCB distance of the capacitor from the IC make a difference ? or the capacitance will apply regardless

Regards

Jonathan Kabangu

+1 Haseen Reddy Siripi Reddy 8 months ago in reply to Jonathan Tshimama-Kabangu

Hi Jonathan Kabangu,

If we place the capacitor far way from IC then the trace resistance will increase however only little bit change in the inrush current.

I would recommend you should keep the capacitors close to IC.

Regards,

Haseen.

0 Jonathan Tshimama-Kabangu 8 months ago in reply to Haseen Reddy Siripi Reddy

Hi Haseen,

Thanks for answers,appreciate it

Regards

Jonathan Kabangu

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