LM7480-Q1: Short circuit (Output)

Hi Roy,

LM74700-Q1 anyways can only drive Ideal Diode FET which cannot block forward current (as it can flow through the FET body diode even when the FET is turned OFF). So, output short circuit protection is not possible with LM74700-Q1.

As LM7480-Q1 can drive back-to-back FETs, it is capable of  blocking forward current but it does not have the capability to monitor current/ detect a short circuit and turn OFF the FETs. So, output short circuit protection is not possible by using LM7480-Q1  alone. But LM7480-Q1 along with a current sense amplifier can achieve this as shown below. For more information please refer to section 'Design # 4: Reverse Battery Protection With Overcurrent Protection' of Six System Architectures With Robust Reverse Battery Protection Using an Ideal Diode Controller of Application note.

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Hi Praveen,

If output short issue occurred, I understand that MOSFET may pass the huge current to let MOSFET damaged. But as I know, there is no huge current pass through the LM7480-Q1. If we don't place protection for the status, will the LM7480-Q1 damged?

Regards,

Roy

Hi Roy,

You are right! LM74800-Q1 will not be damaged in the event of short circuit at the output as it is not in the power path. 

Can you please elaborate further on your question, ' If we don't place protection for the status, will the LM7480-Q1 damged?'