TPS568215: minimum softstart time

T Kishi

Part Number: TPS568215

My Customer has question.

The customer wants to set the soft start time to 400 μs or less.
It is a request of the load side Device.
Customer understand that the internal soft start time of TPS568215 is 1 ms,Is it possible to set it to 400us or less?

Best Regard

T Kishi

over 7 years ago

0 Gavin Wang (Zejing) over 7 years ago

TI__Expert 3480 points

Yes, it is possible.
The TPS568215 has an adjustable soft-start time that can be set by connecting a capacitor on SS pin. Pls refer to the equation for the soft-start time (TSS) is shown in Equation 3 in datasheet.

0 Vental Mao over 7 years ago

TI__Expert 5745 points

No, you can't set the Tss less than 1ms by decreasing the Css.
The devices tracks the lower of the internal soft-start voltage or the external soft-start voltage as the reference， which means if the Css less than 10nF, the Vout will track the internal soft-start voltage.
This device is design for high current, so we don't want to set short start-up time.
What's the working condition of your customer ?

0 T Kishi over 7 years ago in reply to Vental Mao

Genius 4425 points

Hi Vental

Thank you for reply.
Customers do not really want to set SS <1 ms.
However, at the request of the load device, it must be SS<400μs.
We will negotiate with customers to add Load SW.

Best Regard

0 Vental Mao over 7 years ago in reply to T Kishi

TI__Expert 5745 points

OK, if you have any other problems ,let me know

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TPS568215: minimum softstart time