failure (shorted) of MoSFET power switch ( BTS50085-1TMB)

[mess123]

Hi could anyone help me figure out why the MOSFET switch (BTS50085-1TMB) is failing short i.e. the drain and source are failed shorted)?? The IC has got a lot of protection circuits. The drain side is connected to Ultra-Capacitors (48V) and the loading is not that big (just few amps 5-10 Amps, little inductive loads).

Thanks in advance. Any help will be highly appreciated.

 

[jpanhalt]

Can you give a schematic? To which side is the load connected? If it is on the source, how are you driving the gate?

John

 

[alexan_e]

mess123 when your question involves a device it is best to include a link to the datasheet so that anyone can access it without having to search.
Datasheet:

@jpanhalt:
This is a smart high side switch so it is connected in the high side, the device is turned on when the input is grounded

Alex

 

[mess123]

Thanks Alex.
Here is the Schematic. KS-CP and Vi-24 are are the loads.

 

[Orson Cart]

You may have the device connected slightly wrong (on the pcb), or the heatsinking may not be sufficient (although it is supposed to be temp limited) - a picture of the hardware along with a picture of the heatsinking used device would be helpful, check that the parts are OK before you use them too! Regards, Orson Cart.

 

[stoffel15]

I have the same thermal problems with the BTS50085 ( I used the same schematics). If I have the supply voltage at 50V, the BTS50085 will overheat.
Has anyone found a solution?