TPS2546: Slow discharge @ OUT

Antony Lin

Part Number: TPS2546

Hi,

Customer encounter an issue that the voltage @ OUT pin discharge very slow. When they turned off the whole system and turn off 5V @ IN as well, they can see there's still 3.7V @ OUT. THere's still 2V @ OUT even after 14 hrs.

Their TPS2546 is placed on a main board with a connector connected to the daughter board. The capacitors of OUT signal is placed @ daughter board as below connected to the USB connector @ daughter board as well. Please suggest what we can check to clarify this.

THanks,

Antony

over 2 years ago

0 Raymond Lin over 2 years ago

TI__Mastermind 25596 points

Hi Antony,

I would need some time to look into this as I'm not too familiar with this device. What is the total capacitance at OUT you sent?

Regards,

Raymond Lin

0 Antony Lin over 2 years ago in reply to Raymond Lin

TI__Genius 13480 points

HI ,

As shown in the partial schematics I attached, the OUT capacitance includes 220uF + 0.1uF x2 + 470pF +1000pF

Thanks,

Antony

0 Raymond Lin over 2 years ago in reply to Antony Lin

TI__Mastermind 25596 points

Hi Antony,

Let me see if someone on the team can help answer this question, thank you for your patience.

Regards,

Raymond Lin

0 Raymond Lin over 2 years ago in reply to Antony Lin

TI__Mastermind 25596 points

Hi Antony,

The discharge function should only work when the IN pin is powered. Does the OUT discharge once they reapply 5V or set EN low? Those conditions should cause the switch to open and discharge OUT.

Regards,

Raymond Lin

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TPS2546: Slow discharge @ OUT