LM5141-Q1: LM5141 external resistor current sensing design

Jingyuan Zhao1

Part Number: LM5141-Q1

Hi team,

This thread really helps. So what's the purpose of adding R9 on EVM? Any instruction document on how to adjust R8,R9, C19 when parasitics issues happen on a real board except adjusting RC frequency?

Thanks so much.

Best regards,

Charles Zhao

over 6 years ago

0 David Baba over 6 years ago

TI__Mastermind 40040 points

Hello Jingyuan,

The R8 and C19 is useful for taking care of the L/R parasitic of the Rsense. Where L is the ESL of the Rsense and R is the actual Rsense value.

Set R8 = L/Rsense/C10

R9 is just a place holder to filter Vout noise. keep at 0hms. Perhaps a 10 to 100ohm maybe helpful if needed depediing on design/layout?

Hope this helps?

David.

0 Jingyuan Zhao1 over 6 years ago in reply to David Baba

TI__Prodigy 440 points

Hi David,

This solves my questions perfectly. Thanks so much!

Best regards,

Charles Zhao

Power management

Power management forum

LM5141-Q1: LM5141 external resistor current sensing design