# Inductive energy when 12V relay coil is released

Maybe this question is non-sense. If I have a commom 12V relay (12V, 400 ohms coil) WITHOUT having a flyback diode connected to it, and driven by a low-side protected transistor/IC like ZXMS6004FF (the internal over-voltage protection would do the diode job). The datasheet of the transistor shows it withstands to a 90mJ "Unclamped Single Pulse Inductive Energy".

This is for a very specific project question. Would the transistor get damaged?

Datasheet of ZXMS6004FF: https://www.diodes.com/assets/Datasheets/ZXMS6004FF.pdf

You need to know the inductance of the relay coil. Then you can calculate the total energy of the coil by $$\ E= \frac {1}{2}LI^2 \$$ and compare that to 90 mJ.
est.L=4H +/-50%, I=12/400=0.03A $$\ E= \frac {1}{2}LI^2 \$$ =1.8mJ +/-50% seems well under 90mJ