TPS54327: Recommended OFF-ON time

Koji Hayashi92

Mastermind 6970 points

Part Number: TPS54327

Hi Ti-team

TPS54327 don't have sinkTr.

When EN is turned off, I think that the output decreases through the resistance of FB.

I think that long time for the output voltage to drop.

Does the problem occur when the OFF to ON time is short ?

For example, reverse current flows in the coil.

How long should it be from OFF to ON time ?

I think it will change depending on Cout and Rfb, so please tell me the calculation method.

Best Regards,
Koji Hayashi

over 4 years ago

0 Jason Wang (BSR-MV) over 4 years ago

TI__Genius 9550 points

hi,

I am looking into your request and will give you feedback on Monday.

0 Iven Su over 4 years ago

TI__Expert 8245 points

Hi,

There's no obvious problem found when EN changes from OFF to ON, the device will soft start first which is very smooth. Thanks.

0 Koji Hayashi92 over 4 years ago in reply to Iven Su

Mastermind 6970 points

Hi Iven-san

Thank you for response.

During soft start, I think that the FB voltage is higher than the set voltage.

Does low side turn ON and reverse current flows ?

Is Jason-san's answer the same ?

Best Regards,
Koji Hayashi

0 Iven Su over 4 years ago in reply to Koji Hayashi92

TI__Expert 8245 points

Hi,

The device has a prebiased soft start function which prevents the initial sinking of the prebias output. You can refer to its datasheet for the details. Thanks.

0 Koji Hayashi92 over 4 years ago in reply to Iven Su

Mastermind 6970 points

Hi Iven-san

Thank you for response.

I underestand.

Best Regards,

Koji Hayashi

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TPS54327: Recommended OFF-ON time