TPS2660: Improving Surge Tolerance

Kuramochi Tadahiko

Guru 28715 points

Part Number: TPS2660

Hi,

My customer is evaluating TPS26620, however IN pin is damaged by their surge test.

Is there any good solution to improve the surge tolerant of IN pin?

Best Regards,

Kuramochi

over 4 years ago

0 Rakesh over 4 years ago

TI__Guru** 105361 points

Hi Kuramochi,

Which TVS diode is used at the input ? Can you share the schematic

Best Regards, Rakesh

0 Kuramochi Tadahiko over 4 years ago in reply to Rakesh

Guru 28715 points

Hi Rakesh-san,

Thank you for your reply.

They use SMCJ30CA.

The schematic is the almost same as EVM, it was changed based on the following thread.

https://e2e.ti.com/support/power-management/f/196/p/929099/3432804#3432804

Best Regards,

Kuramochi

0 Rakesh over 4 years ago in reply to Kuramochi Tadahiko

TI__Guru** 105361 points

Hi Kuramochi,

Can you please share the surge profile used for the test. what is the coupling impedance ?

Best Regards, Rakesh

0 Kuramochi Tadahiko over 4 years ago in reply to Rakesh

Guru 28715 points

Hi Rakesh-san,

They are using the following equipment.

http://www.noiseken.com/uploads/photos0/182.pdf

Please refer page.7 regarding the surge profile.

The coupling impedance is as below;

Best Regards,

Kuramochi

0 Rakesh over 4 years ago in reply to Kuramochi Tadahiko

TI__Guru** 105361 points

Hi Kuramochi-san,

What is the Open-circuit test voltage kV ? Is the transient voltage exceeding the abs max rating of eFuse ?

0 Kuramochi Tadahiko over 4 years ago in reply to Rakesh

Guru 28715 points

Hi Rakesh-san,

The test voltage is 1kV ±10%.

They don't check the transient voltage because measurement equipment may be damaged.

Best Regards,

Kuramochi

0 Rakesh over 4 years ago in reply to Kuramochi Tadahiko

TI__Guru** 105361 points

Hi Kuramochi-san,

1kV with 10-Ohm coupling impedance forces surge current of 100A.

SMCJ30A has dynamic impedance of 0.5 Ohm. So, 100A current into SMCJ30A takes the voltage to 33.3V+100A*0.5Ohm = 83.3V which exceeds abs max rating of TPS2660

Using bigger tvs diode SMD type or 10uF ceramic cap with SMCJ30A can help to improve surge tolerance.

Best Regards, Rakesh

0 Rakesh over 4 years ago in reply to Rakesh

TI__Guru** 105361 points

Hi Kuramochi-san,

Does it resolved ?

Best Regards, Rakesh

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TPS2660: Improving Surge Tolerance