Driving a mosfet directly?

[passion1]

I would like to use a power mosfet IRFP460 to switch a 24V circuit.
The IRFP460 is a n-channel mosfet with the following rating:
Vdss = 500 V
Id(cont) = 20A
Rds(on) = 0.27 ohm
Vgs(th) = min 2V max 4V
Vgs continuous gate-to-source 20V

Can I drive this mosfet by connecting the gate directly to my PIC16F73 output port or do I need a mosfet driver?
Also, can I connect the mosfet source directly to the ground of the 24V supply, and drain goes to load with other side of load going to +24VDC?
If a driver is needed, can you recommend a suitable driver.
If a driver is not needed, is it then necessary to put a resistor inbetween I/O pin and gate and if so, what size?
Any help is appreciated.

[Charles Linquis]

You don't need a MOSFET driver, but connecting a small resistor (10 ohms or so) between the PIC output and the FET gate is always a good idea, this helps insure sharp switching with no ringing.

Since you are switching fairly high currents in the vicinity of your PIC, make certain you bypass the PIC well.

[Ioannis]

It depends on the current you need. More current, more drive. Check the Vgs to Id curves. They will reveal the actual drive you will need.

Ioannis

[passion1]

Charles / Ioannis

Thank you for the advice.
Can I connect the mosfet source directly to the ground of a 24-36V supply, and drain goes to load with other side of load going to +36VDC?

[Ioannis]

You should take care if the load is noisy. Otherwise there is no problem in that connection.

Ioannis

[paul borgmeier]

Also remember that the 16F73 output is VDD-0.7VDC. If you are you using 5.0V for the PIC VDD, your max Vgs will be 4.3VDC. (Your selected FET can have a Vgs threshold of 4.0 VDC !!). You won't be able to get much IDrain Current, possibly 3A max. If it were me (with what I know about your application and what you are driving), I would switch to a FET that was more logic-level friendly like the IRL520 (or something similar). Otherwise I would look at adding a driver near 10Vdc.

By the way, what are you driving and what amperage do you need?