Yup, changing a power mosfet with another power mosfet shouldnt matter much because the high capacitance is coming from the big physical geometry required to channel big currents, and that is more or less the case for all power mosfets, of course depending on ratings and such, but generally speaking it may vary some, but wont drastically change.
Which means the thing needed to change is the driving circuitry. The reasoning chain is as follows. Could use 2 mosfets with 2-3 resistors, but would lack performance. Disadvantage is that the mosfets are probably low current and hence require series resistors in line with the gate, hence the rise and fall times will be inherently slow. Besides, populating the pcb with 2 mosfets and 3 resistors isnt as easy are using one single driver. At some extent may find some p- and n- channel paired mosfets in same 8 pin package, with mid-current ratings, that could be used with some resistors, but again we can go straight to mosfet drivers, probably at similar price, and less complications. And the driver is made specifically for the job, hence this solution should be faster and much better.
If we do go with mosfet drivers, I think the that one with 1.5A is too low, e.g. the math in previous post was 2.35A and i think there are mosfets with double value for total gate charge. A better choice is perhaps TC4422A, or TC4452, these have 9A and 12A peaks, these were my previous choice. Probably all driver types are more or less around same price, e.g. they probably have the same wafer hex size so should cost about the same so i'd personally rather go with higher current ones. Besides this reasoning, once a circuit is launched around ppls will play with it, copy it, and replace mosfet with who knows which one, so i'd rather go with a driver that can handle everything rather than a driver that has ratings very close to a specific component.
After the one time peaks math out, what normally matters is the switching frequency which makes the power dissipation, to be under the max allowed. But i dont think this is a real issue in this context, I think these variants should have no trouble to drive fets at much more than 100khz, (datasheet graphs are very generous), while the current arduino pid frequency is probably something like less than 80-60khz. Even for a board that could do more than that, probably the firmware wont do that, coz it would tend to maintain compatibility with circuits that do not have mosfet drivers, and those need longer rise/fall times, hence lower frequency. And besides that, when increasing that frequency of a uC output pin, probably the quality of the waveform should deform progressively, so its probably not a good idea to push it too much anyway. Especially coz in our case its not even needed and after some point the only thing it does is to increase the power losses and dissipation without any extra utility. So a frequency that is reasonable for our extruders is not expected to be a real criteria (for mosfet drivers), although normally it should be (for direct driving mosfet or for discrete parts). Basically with mosfet drivers the interval is probably larger than any other driving solution.
Which means the thing needed to change is the driving circuitry. The reasoning chain is as follows. Could use 2 mosfets with 2-3 resistors, but would lack performance. Disadvantage is that the mosfets are probably low current and hence require series resistors in line with the gate, hence the rise and fall times will be inherently slow. Besides, populating the pcb with 2 mosfets and 3 resistors isnt as easy are using one single driver. At some extent may find some p- and n- channel paired mosfets in same 8 pin package, with mid-current ratings, that could be used with some resistors, but again we can go straight to mosfet drivers, probably at similar price, and less complications. And the driver is made specifically for the job, hence this solution should be faster and much better.
If we do go with mosfet drivers, I think the that one with 1.5A is too low, e.g. the math in previous post was 2.35A and i think there are mosfets with double value for total gate charge. A better choice is perhaps TC4422A, or TC4452, these have 9A and 12A peaks, these were my previous choice. Probably all driver types are more or less around same price, e.g. they probably have the same wafer hex size so should cost about the same so i'd personally rather go with higher current ones. Besides this reasoning, once a circuit is launched around ppls will play with it, copy it, and replace mosfet with who knows which one, so i'd rather go with a driver that can handle everything rather than a driver that has ratings very close to a specific component.
After the one time peaks math out, what normally matters is the switching frequency which makes the power dissipation, to be under the max allowed. But i dont think this is a real issue in this context, I think these variants should have no trouble to drive fets at much more than 100khz, (datasheet graphs are very generous), while the current arduino pid frequency is probably something like less than 80-60khz. Even for a board that could do more than that, probably the firmware wont do that, coz it would tend to maintain compatibility with circuits that do not have mosfet drivers, and those need longer rise/fall times, hence lower frequency. And besides that, when increasing that frequency of a uC output pin, probably the quality of the waveform should deform progressively, so its probably not a good idea to push it too much anyway. Especially coz in our case its not even needed and after some point the only thing it does is to increase the power losses and dissipation without any extra utility. So a frequency that is reasonable for our extruders is not expected to be a real criteria (for mosfet drivers), although normally it should be (for direct driving mosfet or for discrete parts). Basically with mosfet drivers the interval is probably larger than any other driving solution.