TPS1663: eFuse IC damage issue during connector disconnection and connection test

JH Shin

Part Number: TPS1663

Tool/software:

Hello,

My customer is using TPS16630RGER and TPS2420RSAR for circuit protection on 50.2V and 12V inputs coming from connectors.

hot swap CD.pdf

During the connection and disconnection test to verify the protection circuit operation, the input pin of the TPS16630RGER was damaged as shown in the photo below.

Q1. Please review the circuit design and PCB design of TPS16630RGER and TPS2420RSAR shared above to see if there are any problems.

Q2. Please advise on what is causing the problem and how to solve it.

Q3. If the TPS16630RGER or TPS2420RSAR IC are damaged, is there a possibility that the INPUT PIN will be shorted to GND?

Thank you.

5 days ago

0 Amrit Jit 4 days ago

TI__Mastermind 30681 points

Hello JH,

There is no TVS diode at output. I believe trainset voltage at input violates the abs max voltage of the device.

Please incorporate TVS diode in your design. Below is TVS selection guide for this device.

https://dr-download.ti.com/design-tools-simulation/calculation-tool/MD-9eu0p1l7Co/1.0.0/TVS_Recommendation_Tool.zip

ADJ article below.

https://www.ti.com/lit/an/slyt862/slyt862.pdf?ts=1756734834722&ref_url=https%253A%252F%252Fwww.google.com%252F

Thanks

Amrit

0 JH Shin 3 days ago in reply to Amrit Jit

Guru 10890 points

Hi Amrit,

Thank you for your reply.

Below are our customers' responses and inquiries.

TVS is used between the connector and IC input terminal as shown below.

- 50.2V : P4SMA62A

- 12V : MSMP15A

Please provide TI's opinion on the above Q1 and Q3 inquiries.

Best Regards,

0 Amrit Jit 2 days ago in reply to JH Shin

TI__Mastermind 30681 points

Hello Shin,

Q1. schematic and layout of TPS663 looking fine to me. You can consider Schottky diode and COUT at output in case of negative voltage because of path inductance.

Q3. Yes, there is possibility of VIN to GND short.

During abs max violation, it’s the over voltage, it is the overvoltage that can open unintended current paths such as forward or reverse breakdown of diodes or oxides reaching their breakdown voltage within integrated circuits (ICs). Once an overvoltage opens an unintended current path, the resulting currents can cause damage that includes the melting of silicon; the fusing of metal interconnects; thermal damage to packaging material; and the fusing of bond-wires, leading to electrically induced physical damage (EIPD).

Thanks

Amrit

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TPS1663: eFuse IC damage issue during connector disconnection and connection test