TPS54386: EMI fail

Raymond He

Expert 1990 points

Part Number: TPS54386

dear

TPS54170+TPS54386TPWPRQ power swith frequency show as bellow

TPS54170+TPS54386TPWPRQ EMI fail and ADI LT8530 pass, is there solution about reduce EMI radiation? thanks in advance

over 2 years ago

0 Zhao Ma over 2 years ago

TI__Genius 15135 points

Hi, He

Could you send me the schematic?

I didn't find the datasheet of TPS54170, it is a custom device?

which device is the 1st stage converter of this application?

0 Raymond He over 2 years ago

Expert 1990 points

TPS57140 is the right PN

0 Raymond He over 2 years ago in reply to Zhao Ma

Expert 1990 points

TPS57140 is the right pN, sch show as below,thanks

0 Zhao Ma over 2 years ago in reply to Raymond He

TI__Genius 15135 points

Hi, He

1. Confirm the result with you, is below correct?

"TPS57140 +TPS54386" --> EMI fail??

"TPS57140 +LT8530" --> EMI pass??

2. I cannot find LT8530 too, what is the LT8530? is it a buck converter?

Comments for improve EMI performance:

1. Add 2*0.1uF for tps54386, one is placed close to PVDD1 in layout, the other is placed close to PVDD2 in layout.

2. Besides, the EMI performance is usually determined by 1st stage converter, so we should focus on TPS57140, maybe you can post another thread to ask how to improve TPS57140 EMI.

0 Raymond He over 2 years ago in reply to Zhao Ma

Expert 1990 points

LT8650SIV------EMI PASS

TPS57140 +TPS54386" --> EMI fail

0 Zhao Ma over 2 years ago in reply to Raymond He

TI__Genius 15135 points

Ok, suggest below method to improve the EMI performance.

Add 2*0.1uF for tps54386, one is placed close to PVDD1 in layout, the other is placed close to PVDD2 in layout.

0 Lucia Gao over 2 years ago in reply to Raymond He

TI__Genius 16600 points

Hi ,
Sorry that I will close this threat first. Please re-open it if there is any future question.
BRs,
Lucia

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TPS54386: EMI fail