In series or in parallel? Using PWM? If so what frequency? Higher speeds of PWM would really need a MOSFET driver chip to get fast switching.If you want to drive the MOSFET directly from an Arduino you _must_ get a logic-level FET.What maximum current are you needing and what's the power supply(see my first question)? You need to calculatethe power dissipation in the FET using I-squared-R (ignore the nominal current rating of a MOSFET,its only applicable if using extreme cooling measures).
OK, so you need a very low Rds(on) device - heat dissipation is I-squared-R, so if the device were 10 milliohm thatwould be 8W dissipated when on, which would need a reasonable amount of cooling (something like a chipsetheatsink and fan perhaps?). If you got a 3 milliohm device you'd run a lot cooler or need less heatsinking.I've used an IRLS3036 in the past, its logic level, has 60V rating and 2 milliohm. However its surface-mount only.I'd recommend trying to get a device with Vds voltage rating of 20V or more, about 5 milliohm Rds(on) or thereaboutsand logic-level - TO220 package is probably easiest to heatsink (remember the drain terminal is also connected electricallyto the tab, so you need an insulating heat-conducting pad between package and heat-sink.Another approach is to parallel a couple of devices to get half the Rds(on) figure - then 10 to 15 milliohm devices would be more feasible.
Please enter a valid email to subscribe
We need to confirm your email address.
To complete the subscription, please click the link in the
email we just sent you.
Thank you for subscribing!
via Egeo 16