I'm testing a DC motor using a power MOSFET and an H-bridge circuit, but I can't control it and the MOSFET gets damaged. I'm using the following specifications.
- DC power supply: DC5-16V
- DC current: 0-25A
If normal rotation, reverse rotation, and stop is repeated continuously, the n-channel MOSFET heats up and becomes damaged. There is a 10 msec interval switching between each control. If only normal and reverse rotation are performed, there is no problem, but if rotation is stopped the n-channel MOSFET is damaged when it is turned on. What could be the cause of the damage?
- Is heat sink of a sufficient size?
If the heat sink is small, thermal resistance will be high and channel temperature will rise. If the rated channel temperature is exceeded, this could result in damage.
- Are you turning on the p-channel MOSFET and n-channel MOSFET of the H-bridge circuit simultaneously?
If the connected p-channel and n-channel MOSFETs are turned on simultaneously, penetration current flows into the MOSFETs and could cause damage.
- Is any external power being applied to the DC motor (and generating power)?
If power is being generated the power supply voltage will rise, and may go overvoltage, causing damage.
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