TPS65987D: Snubber on VBUS

Antony Lin

Part Number: TPS65987D
Other Parts Discussed in Thread: TVS2200

Hi,

We suggest a snubber circuit in datasheet as below. Can customer change the resistor to 4.7ohm since 3.48ohm resistor is not available?

Thanks!

Antony

over 7 years ago

0 Adam Mc Gaffin over 7 years ago

TI__Mastermind 30000 points

Hi Antony,

I would recommend staying with the component values listed as they have been specifically chosen to support up to 4 m USB Type-C cable (maximum length allowed in the USB Type-C specification) being hot plugged. If the customer wishes to not use the 3.48 ohm resistor, then they will have to recalculate the RC circuit to find the correct series capacitance since 4.7uF may not be to correct value in series with 4.7 ohms.

Regards,
Adam

0 Antony Lin over 7 years ago in reply to Adam Mc Gaffin

TI__Genius 13480 points

Hi Adam,

Thanks. Can you show us how to calculate the cap value for 4.7 ohm?

Thx.

Antony

0 Adam Mc Gaffin over 7 years ago in reply to Antony Lin

TI__Mastermind 30000 points

Hello Antony,

Speaking with the individual who created the reference design, we both recommend sticking with what is within the datasheet. The schematic was simulated within Tina, and a few assumptions were made based on cable composition/end application. We believe that changing these values will have an effect on the overall performance of the snubber. If the 3.48 ohm resistor cannot be used or found, the customer can use a TVS diode instead such as the TVS2200

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TPS65987D: Snubber on VBUS