Resistor damage/broken after BCI test

[Kick]

Hi all,

What could be the reason for Resistor failure during/after the BCI test?

Resistor: SMD 47ohm 5% 0.4W 0805
BCI severity level: 130mA
Supply voltage; 5V

As per the formula, Power = Voltage x Current
= 5 x 0.13 = 0.65W, which is more than the specification of Resistors.

Is my calculation right?

In my research I got few more reason for failure.
1. Exposure to ESD or surge
2. Excessive load.

If I go with alternative R, what would be the value?

Anyone has any idea about this failure??

Thanks in advance!

 

[stenzer]

Hi,

to be hornest the resistor looks to me like it has been mechanically destroyed.

To consider a failure by means of excessive load, the actual installation point of this resistor would be of interest as the disturbance is entering the DUT along the (supply) lines. Also the specific resistor would be of interest, by means of pulse power handling. Here I'm not familiar how long the external current is injected, by menas of its ON and OFF-duration, between the individual frequencies.

BR

 

[KlausST]

Hi,

neither 5V nor 130mA explains a damage like this.

ESD has too low energy for this damage, either.

Power = Voltage x Current

does not apply here because you use 47R
so either use I x I x R or U x U / R .. depending on the real situation.

Klaus