TPS4811-Q1: How to add external circuit to achieve reverse protection

Jimmy WANG

Genius 4085 points

Part Number: TPS4811-Q1
Other Parts Discussed in Thread: TPS1211-Q1, TPS1211Q1EVM,

Tool/software:

Hi team,

How to add external circuit to achieve reverse protection? thanks

23 days ago

0 Rishika Patel 22 days ago

TI__Expert 8001 points

Hi Jimmy,

Please see section 9.3 Typical Application: Reverse Polarity Protection with TPS12110-Q1 in the TPS1211-Q1 datasheet on how to use external circuitry for input reverse polarity protection. This device has output reverse polarity protection down to –30V. This is also implemented in the TPS1211Q1EVM so you can refer to the user's guide to see the schematic.

Thanks,

Rishika Patel

0 Jimmy WANG 22 days ago in reply to Rishika Patel

Genius 4085 points

Hi team,

Does this design can change to -48V input reverse?

0 Rishika Patel 21 days ago in reply to Jimmy WANG

TI__Expert 8001 points

Hi Jimmy,

I am checking on this, I will get back to you.

Thanks,

Rishika Patel

0 Jimmy WANG 19 days ago in reply to Rishika Patel

Genius 4085 points

Hi team,

What is the function of D10 and D11? thansk

0 Rishika Patel 18 days ago in reply to Jimmy WANG

TI__Expert 8001 points

Hi Jimmy,

Yes, you can use the input reverse polarity protection circuit for a 48V application.

D10/D11 are used as an ORing configuration to power the input supply; so, VOUT can be used to power VS if the other supply is not active.

Thanks,

Rishika Patel

0 Jimmy WANG 18 days ago in reply to Rishika Patel

Genius 4085 points

Hi team,

What circuit is reverse polarity protection circuit for a 48V application.

D10 or below pic? What component value needs to change? thanks

0 Rishika Patel 17 days ago in reply to Jimmy WANG

TI__Expert 8001 points

Hi Jimmy,

The yellow box shows the input reverse polarity protection. Those components must be rated accordingly. Please see section 9.3 Typical Application: Reverse Polarity Protection with TPS12110-Q1 in the TPS1211-Q1 datasheet on how to use external circuitry for input reverse polarity protection. This is the same circuit that can be used for the TPS4811-Q1.

Thanks,

Rishika Patel

0 Jimmy WANG 17 days ago in reply to Rishika Patel

Genius 4085 points

Hi team,

I checked the circuit in the datasheet. But no defined how to choose Rbias and D1,Q1.

Do you have any suggestions? thanks

0 Rishika Patel 16 days ago in reply to Jimmy WANG

TI__Expert 8001 points

Hi Jimmy,

I am checking on this, I will get back to you.

Thanks,

Rishika Patel

+1 Rishika Patel 14 days ago in reply to Rishika Patel

TI__Expert 8001 points

Hi Jimmy,

In the TPS1211EVM, 10k is used as RBIAS for current limiting to the gate.

The N-MOSFET in the ground path protects the controller, and Zener diode is added for VGS protection of the ground path FET (12V typically - make sure to not exceed the FET ratings). The FET VGS should be rated for the max VS the device will see especially in a reverse polarity event.

Please let me know if you have any more questions.

Thanks,

Rishika Patel

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TPS4811-Q1: How to add external circuit to achieve reverse protection