LM5141QRGEVM: Current sensing input RC filter

Kallikuppa Sreenivasa

Part Number: LM5141QRGEVM

Hi Power Experts,

I have a couple of questions regarding the current sensing circuit highlighted in the below diagram,

Do we need to have the RC filter for the current sense input. What is the effect on the performance if the RC filter is not used?

Can you also help us understand the effect on the DC/DC performance if we do not follow the kelvin sensing.

Thank you for the guidance.

Regards,

Sreenivasa

over 2 years ago

+1 Timothy Hegarty over 2 years ago

TI__Guru 69947 points

Hello,

The RC filter on the current sense is just to remove high-frequency noise. It's more common on designs with higher inductance value that has lower self-resonant freqeuncy (higher parasitic capacitance). Most designs do not need it.

The sense line should Kelvin to the shunt at the center of the inside edge of the pads. This optimizes current sense accuracy for current limit.

Regards,

Tim

0 Kallikuppa Sreenivasa over 2 years ago in reply to Timothy Hegarty

TI__Guru**** 181619 points

Hello Tim,

Thank you for the explanation and noted.

Regards,

Sreenivasa

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LM5141QRGEVM: Current sensing input RC filter