TPS2375: TPS2375 INRUSH

SWENGWOO LEE

Part Number: TPS2375

I'm currently using TPS2375, and after a successful PD negotiation, it supplies power to the DCDC converter to generate 12V.

However, when I turn off and on the DCDC converter again, it seems that TPS2375 is triggering the current limit due to INRUSH.

Is there a solution to address this issue?

over 1 year ago

0 Diang Xing over 1 year ago

TI__Mastermind 37111 points

Hi SWENGWOO,

Thanks for reaching out to us.

Could you share the schematic with TPS2375?

Best regards,

Diang

0 SWENGWOO LEE over 1 year ago in reply to Diang Xing

Intellectual 270 points

It seems difficult to share the circuit diagram due to company regulations.

Is it possible to understand the information without sharing the circuit diagram?

0 Diang Xing over 1 year ago in reply to SWENGWOO LEE

TI__Mastermind 37111 points

Hi SWENGWOO,

May I know how much is your inrush current limit resistance? Looks like your current is already reaches 405 - 515 mA the overcurrent protection current.

Besides, do you have any capacitor with PG pin? Probably the PG voltage does not fully been discharged and causes the DC/DC startup too early.

Best regards,

Diang

0 SWENGWOO LEE over 1 year ago in reply to Diang Xing

Intellectual 270 points

HIThank you for your response. I am currently using a 68k current limit resistance, and the PG pin is in a floating state.

0 Diang Xing over 1 year ago in reply to SWENGWOO LEE

TI__Mastermind 37111 points

Hi SWENGWOO,

Thanks for your quick reply. Making PG floating could be a risk since the downstream circuit after the PD may start up in PD's inrush period. During PD inrush period the RTN-VSS current will be clamped to inrush limit.

Could you help to track the PoE power interface current, and the downstream DC/DC's gate signal? I want to see when the DC/DC starts to check if it will be a potential issue.

Best regards,

Diang

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TPS2375: TPS2375 INRUSH