Suggestion for Conducted emission test Failure

Suhan Shetty

Prodigy 165 points

Dear Selva,

We are facing some issue in conducted emission test.

We are using below regulators in our design.

LMR23625CQDDARQ1

TLV71333PQDBVRQ1

TPS62065QDSGRQ1

TPS61240TDRVRQ1

Failure graph attached for your reference.

Test Standard : CISPR 25

Bandwidth : 120Khz

Please let us know your suggestion to resolve this issue.

Regards,

Suhan Shetty

over 4 years ago

0 Daniel Li14 over 4 years ago

TI__Mastermind 27470 points

HI Shetty：

can you try to add some boot resistor at boot pin to slow downt the SW slew rate, and can you share the schematic and layout?

one more choice is shield the dcdc which may be helpful

Thanks

0 Timothy Hegarty over 4 years ago in reply to Daniel Li14

TI__Guru* 75542 points

Hi Suhan,

Given the high frequency of the CISPR 25 conducted emissions test, you may need common-mode (CM) input filtering using a common-mode choke. Please refer to this e-book on EMI for further guidance: www.ti.com/lit/slyy208

Also, see part 16 here for CM input filter design: http://www.how2power.com/other/EMI_Guide.php

Regards,

Tim

0 Suhan Shetty over 4 years ago in reply to Daniel Li14

Prodigy 165 points

Mr. Rajan Selva Kumaran will share the schematic & board file.

0 Timothy Hegarty over 4 years ago in reply to Suhan Shetty

TI__Guru* 75542 points

Ok, thank you.

Power management

Power management forum

Suggestion for Conducted emission test Failure