Over Temperature Issue on 50XS4200

[GuruPrakashR]

Hi Team,

I am Working on MC50XS4200 High-side switch. I am trying to implement auto retry function as I am getting hit with over current issue. The Auto retry is also keep on failing. Current limit is 15. Upon further investigation I found it to be Overtemperature fault setting in added to that. According to data sheet OT will set only when Junction temperature is above 175 degrees. I could see the OT = OD2 setting in. But I am not sure the junction temperature will be that much to hit OT. So I wanted to check is it any other way this OT can set in.

1. Like because of retries or any other factor.

2. Also wanted to understand can it be caused due to Over current. if so, is there any value for that eg. Over current XX A at XX sec can cause the issue.

3. Is there any current and time graph you have related to this if over current can cause this issue.

[Bonnie219Bailey]

Hello!

Your MC50XS4200 high-side switch is likely hitting an overtemperature (OT) fault, even if the steady-state junction temperature isn't usually 175°C, because repeated overcurrent auto-retries cause significant power dissipation, leading to a cumulative rise in junction temperature. Each retry generates heat (I
2
×R
DS(on)
​
), and insufficient cool-down time between attempts can quickly push the die temperature past the OT threshold. Overcurrent is the primary cause of this heating; while there's no fixed "XX A at XX sec" value due to varying thermal impedances and ambient conditions, the datasheet's thermal characteristics (like R
thJA
​
, R
thJC
​
, and transient thermal impedance curves) are crucial for understanding this dynamic, as they explain how current spikes translate into rapid temperature increases.

[GuruPrakashR]

Understood. In that case how to mitigate this problem. Is there any solution. where can i access any material or detail regarding this. Because of this OT I couldn't make auto retry work. Then system is goes offline totally.