Timeline for Why is this MOSFET getting very hot?
Current License: CC BY-SA 3.0
7 events
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| Jun 18, 2013 at 2:22 | comment | added | Connor Wolf | @raforanz - as Wouter van Ooijen said, at high duty cycles, the FET gate is never discharging below the fully saturated point. As such, the FET is basically completely on continuously, which means it won't exhibit much self-heating. On the other hand, it also means that you no longer have proportional control of the motor. I suspect that you are basically reaching full-power at ~70-90% duty cycle, and any further increase causes no change in the motor power. | |
| Jun 17, 2013 at 7:29 | comment | added | Wouter van Ooijen | I suspect that with a high duty cycle the mosfet will be permanently on (due to the 10uF capacitor). | |
| Jun 17, 2013 at 7:26 | comment | added | raforanz | if gate voltage is a cause for the heat ,why its not getting heated at Full duty cycles as the gate voltage is always the same for the given circuit irrespective of the pwm duty cycle. I hope my doubt would be cleared | |
| Jun 17, 2013 at 7:16 | comment | added | raforanz | It was a mistake that I put it as 244khz, its actually 244Hz. Any changes in answer? | |
| Jun 17, 2013 at 7:05 | history | edited | Connor Wolf | CC BY-SA 3.0 |
added 690 characters in body
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| Jun 17, 2013 at 6:58 | comment | added | Wouter van Ooijen | Also note that a rating figure like 49A in the datasheet is under the most optimistic of circumstances: ao. good gate driving, and a lot of cooling. | |
| Jun 17, 2013 at 6:54 | history | answered | Connor Wolf | CC BY-SA 3.0 |