IPS2050H short circuit protection

[Fredda]

Can the IPS2050H withstand a full short circuit on the outputs?

Let's say the IPS2050H output is connected to a board power connector. What happens if:

1. The connector is first short circuited and then the IPS2050H is turned on.

2. The IPS2050H is already turned on and then the connector is short circuited.

/F

[Peter BENSCH · Accepted solution]

Welcome @Fredda, to the community!

yes, the IPS2050H is protected against short circuits at its outputs, so that both cases would be covered. Please see the data sheet, section 7.3, and AN5784, section 3, for more details about the different possibilities.

Does it answer your question?

Regards
/Peter

[Fredda]

Thanks. Ok, that sounds good. I'm gonna get my hands on a STEVAL-IFP043V1 board and try it out.

Regards

/F

[Fredda]

Hi,

I've tested the IPS2050H short circuit protection with the STEVAL-IFP043V1 board and unfortunately it didn't go well.

Test setup according to below picture. IPD1 is connected to IN1 via 220 kohm resistor. Board powered with a 24V/15A PSU. The short circuit is introduced by inserting a connector with shortcircuited terminals. This resulted in a bang, a flash and a hole in the IC. 

/Fredda

[Milos_Hofman]

Hi Fredda,

thanks for sharing your experience. It looks crazy, let's try to fix the issue ;).

We have realized, the J3 jumper on your STEVAL is left open. This means the Transil Diode at the supply terminal is not involved. There are pulses with very di/dt during the short circuit, which may create an excessive overvoltage spikes on the supply bus due to parasitic wiring inductances etc. These overvoltage spikes may exceed the absolute ratings of the IPS2050HQ-32 and it may get destroyed.

Would you please try to insert J3? In that case, the overvoltage on the supply rail will be limited and the IPS2050HQ-32 properly protected.

I am looking forward to hearing from you any updates.

Have a nice day,
Milos

Technical Marketing / EMEA

[Fredda]

Hi,

That seems like a reasonable analysis of the situation. Juts need to order a couple of new boards! :)

For 48 V applications, do you recommend a TVS diode in the same SM15T, TRANSIL series? Like the SM15T68A/CA.

/F

[Fredda]

By the way, it seems like a bond wire to pin 6 (GND) has vaporized and exploded. Judging by the exposed straight channel in the crater.

[Milos_Hofman]

To select the right TVS at 48V applications is a bit more challenging. There is a bigger voltage jump in the SM15T portfolio, so the very next one is really the SM15T68A/CA as you write. Unfortunately, it has already too high clamping voltage and therefore would not protect the IC properly. I would suggest to look rather at the SMC30J48A/CA or eventually even SMC50J48A/CA.

Milos

[Fredda]

I've finally had the chance to short circuit the Power Switch with the TVS connected. It seems like the TVS is doing its job and protecting the switch from an excessive overvoltage. Great!

Short circuit

/F

[Milos_Hofman]

Perfect, I am happy to hear that from you! 

Have a nice day