TPS54394: Vout 3.3V and 5V enable 4ms difference

Hui Cao22

Expert 1075 points

Part Number: TPS54394

Tool/software:

Same En pin R and C，but Vout 3.3V and Vout 5V have 4ms difference，what is the reason？

8 months ago

+1 Lucia Gao 8 months ago

TI__Mastermind 30471 points

Dear Sir,

Thank you for reaching out!

R254 is 150k and R249 is 100k. That's the reason why you can find 4ms delay between Vout1 and Vout2 start up. You can double confirm about the value of R254 and R249. Thank you!

BRs

Lucia

0 Hui Cao22 8 months ago in reply to Lucia Gao

Expert 1075 points

what should I set the value of R254 and R249，and why theR254 and R249 can influence the start up？

0 Lucia Gao 8 months ago in reply to Hui Cao22

TI__Mastermind 30471 points

Dear Sir,

The undervoltage-lockout (UVLO) can be adjusted by R254 and R249. It means that with different R254 and R249, the input voltage to enable the device will be different. Thank you!

BRs

Lucia

Power management

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TPS54394: Vout 3.3V and 5V enable 4ms difference