LT8362 output shoots to maximum

Hi,

Death, IC death can be the impact. IC Death by voltage overshoot of the switch, and also death to any other vulnerable components.

The maximum source/sink current for the VC pin is 7uA, and that is a typical number. A sudden pull up of VC tells the converter to deliver as much power as possible, hence the overshoot you see at the output.

Best Regards,

DV

Hi DV, observing similar behavior, not on LT8362, but on the Buck(LT3592) connected next and getting input from LT8362. There is the catastrophic damage to this IC. Though there is bulk capacitor of 35V which is not getting damaged. Also, this behavior is not observed in every boards. Could you please tell the reason?

The reason was provided by you in your first message:

"we are observing Shoot in Output voltage from expected voltage 32V to 59.8V and sometimes to even ~80V",

You should not expect the LT8362 and LT3592 to survive when they are subjected to voltage levels beyond their safe levels.

BR,

DV

I have configured OVLO pin of LT3952 to shutdown at 37.8V. You mean the voltage rise could be so fast that it is out of the fold back time of both the IC's. I mean it can not be controlled either by FBX of LT8362 or by OVLO of LT3592 ?

When you interfere with the LT8362 VC pin, you interfere with its control loop, and the converter runs uncontrolled. That is why the output voltage rises to such high levels. I do not know how fast the LT3592 is to react, but I do know its maximum input voltage is 36V.

BR,

DV

When you interfere with the LT8362 VC pin, you interfere with its control loop, and the converter runs uncontrolled. That is why the output voltage rises to such high levels. I do not know how fast the LT3592 is to react, but I do know its maximum input voltage is 36V.

BR,

DV

just realized.. i made a transposition error.. it's LT3952 what i am using. anyways.. i understood your point. thanks for the help DV.