LM5069: If pin of LM5069 open or shot

Jimmy WANG

Part Number: LM5069

Tool/software:

Hi team,

A customer wanted to know if the LM5069 pins were open or shorted. The IC could still shut down the MOSFET in response to abnormal conditions. The end customer wanted to add a one-time fuse as a last-ditch measure. However, the PCB was running out of space. We hope to address this customer's concerns with TI's professional explanation. For example, the RSN resistor could open if the current exceeds the PD
rating or other explain no need additional fuse. thanks

30 days ago

0 Avishek Pal 29 days ago

TI__Mastermind 39270 points

Thanks for reaching out.

I hope the end customer is looking for a fail-safe mechanism in the design. To achieve the fail-safe mechanism, a fuse has to be added.

Jimmy WANG said:
A customer wanted to know if the LM5069 pins were open or shorted. The IC could still shut down the MOSFET in response to abnormal conditions.

It can't be guaranteed.

0 Jimmy WANG 28 days ago in reply to Avishek Pal

Genius 4065 points

Hi Paul,

But not enough space to add fuse now. I didn't see any design fuse and E-fuse both.

If there is an overcurrent condition, is it possible that the current resistor will be damaged and become open circuit due to the PD rising?

0 Avishek Pal 27 days ago in reply to Jimmy WANG

TI__Mastermind 39270 points

Jimmy WANG said:
If there is an overcurrent condition, is it possible that the current resistor will be damaged and become open circuit due to the PD rising?

No. Because, the current sense resistor is designed to handle the overcurrent threshold safely.

0 Jimmy WANG 27 days ago in reply to Avishek Pal

Genius 4065 points

Hi Paul,

I'm assuming that when the IC fails to properly perform overcurrent protection, the downstream current continues to increase, and the PD rises, causing the current resistor to break and open. Is this possible?

0 Avishek Pal 26 days ago in reply to Jimmy WANG

TI__Mastermind 39270 points

I am not sure. Before damaging the sense resistor, most likely MOSFET will get damaged.

Power management

Power management forum

LM5069: If pin of LM5069 open or shot