Pyro Fuse Circuit

[shubhashd]

I'd like to enquire on one of the application notes for EV pyro fuse. Can it be made standalone/self-triggered?

Here is the application note;

https://www.st.com/resource/en/application_note/an5720-l9679e-cutoff-battery-and-pyro-fuse-stmicroelectronics.pdf

shubhash

[Erwan YVIN]

Hello ,

According the the AN 

This device is family compatible with the L9678,
L9680 and L9679P devices: it has been designed as extension chip of the others, but if configured in the right
way it can be used standalone.

what do you mean about Self-Triggered ?

               Best regards

                           Erwan

[RobLaMoreaux]

I have a similar if not the same question. I have been tasked with doing a design in a few weeks that needs to fire Pyro Fuses when current sensors assert their overcurrent fault flag. I've been told that this needs to be on the order of 50uS so a SPI message would be too slow. From what I can tell the L9679P and L9679e can be told through SPI to deploy and will wait for during the timeout period for a trigger signal.

It looks to me that this could be done using the FENL pin. Could the DCSx pins also cause the L9679P to trigger once a deploy command is sent?

Is there a better way to get this quick of trigger on an overcurrent?

Rob