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Will resistor fail in a few months due to stress?

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eem2am

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Hi,

Is the resistor , R2, in the following schematic going to be overstressed?
-will it fail? , perhaps after a few months in service.?





-It is a standard 0603 SMD resistor with power rating of 100mW.

SCHEMATIC:
https://i51.tinypic.com/28lwbc6.jpg

RESISTOR DATASHEET:
https://www.seielect.com/Catalog/SEI-RMC.pdf

(100R, 0603, RMCF series by Stackpole Electronics)


The power in this resistor peaks up to 240mW , and is above 100mW for 400us when the P mosfet is turned on.
-SO this is above the power rating of the resisitor.


POWER WAVEFORM IN RESISTOR -when FET is turned on.
https://i56.tinypic.com/15efubq.jpg


CURRENT WAVEFORM IN RESISTOR –when FET is turned on.
https://i54.tinypic.com/25sld.jpg



In use , this FET will be switched on/off about ten times per day.
 
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I don't think you have a problem, provided that turnon is at
reasonable temperatures and sparse. Note the derating on
power, from 100% @ 70C to 0% at 150C. The thermal mass
of the resistor ought to keep temperature spike pretty low.
You are way below the current limit. Stackpole may have
info on pulsed power handling if you dig.

If you want to get more margin, put 2, 2X value resistors in
parallel.

You may be able to find higher rated ones with either a
thicker film, or a bulk resistance material. Or go up to an
0804.
 
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