For something that's not switching at a high frequency, slow rise and fall times are fine as long as you are staying within the safe operating area of your MOSFET. A 10K gate resistor could certainly work, but it will depend on your MOSFET and load.
this post was submitted on 27 Dec 2023
9 points (100.0% liked)
Ask Electronics
3325 readers
1 users here now
For questions about component-level electronic circuits, tools and equipment.
Rules
1: Be nice.
2: Be on-topic (eg: Electronic, not electrical).
3: No commercial stuff, buying, selling or valuations.
4: Be safe.
founded 1 year ago
MODERATORS
That's good. My switching frequency is a few times per hour.
I am a little bit concerned that the slow rise/fall time make the MOSFET go outside its operating parameters for a fraction of a second. The resistance gradually changes meaning the mosfet will dissipate more power but also less current will flow.
So if you switch many times per second the gate capacitance with the resistor acts as a low pass filter reducing the gate voltage.
It really depends how much power/current you are switching. If you are switching 1A with a beefy heatsink FET, the time spent in the linear region is short enough it shouldn't be a problem. If you are switching 50A though it then you might have a problem. Depending on how that gate divider is set up, you could still potentially damage the gate of the FET when shorting it to ground to discharge it if I understand how its hooked up correctly.
Ideally you would use some kind of FET driver with a voltage source (e.g. linear regulator) to turn on and off the gate plus the gate resistor.
As long as it fully saturates i thiink it's fine, i've personally only had issues with too slow switching when i switch the mosfet many times a second, or when i didn't give a high enough voltage to fully saturate it, both of which usually led to a smoky mosfet