Logic mosfet

I would like to drive motor using mosfet. I'm looking for one to order from ebay.

The problem I have. After googling I found https://www.sparkfun.com/products/10213

but FQP30N06L datasheet says: 32A, 60V, RDS(on) = 0.035Ω @VGS = 10 V, so it doesnt fully open at 5V or maybe I'm missing something?

And why later it says? VGSS Gate-Source Voltage ± 20 V? what does ± 20 V mean?

Hi KarolisL, What type and size of motor, do you need 30+ Amps? do you need to reverse the motor? The website says it's microcontroller compatable!! so should work with the Arduino, but I have only used much smaller Fets for 1 Amp or so. The RDS varies with voltage and 10V is given as an example, 5v from an Arduino pet set HIGH should switch it ON.

Hope it helps, regards.

Mel.

I will operate stepper up to 10A what would you suggest? simple CW/CCW rotation

  1. The +/-20V is the absolute max Vgs (voltage between gate and source).

  2. A MOSFET rated at 32A is not suitable for a 30A load. No really, believe me.

  3. That MOSFET has a Rds(on) rating also for Vgs = 5V, it IS logic level. Note the
    on resistance is higher at 5V than at 10V, that’s why they quote both.

  4. At 10A that device will need a heatsink and a fan - not a good choice, find one with
    Rds(on) < 0.01 ohms

But to work with 10A motor will it be enough? As I look at characteristics when V_GS = 5, I_D about 30.

Lets say I work with 10A stepper, spikes up 15 (made that up, correct me if I'm wrong). So I^2*R = 225*0.32 = 7.2W. Is that a lot? It says power dissipation 79W. But just to be sure

Why the fascination with e-bay? Buy from a real distributor. A quick search finds this at digikey.com http://www.digikey.com/product-detail/en/AOI514/785-1690-5-ND/3973570 Rds of just .0119ohm at 20A with 4.5V on the gate. With 15A: 15*15*.0119 = 2.675W dissipated in the part If you can drive the gate at 10V, even less, .0059ohm 15*15*.0059 = 1.33W

If you need TO220 package, than this is is a good one http://www.digikey.com/product-detail/en/IRLB8748PBF/IRLB8748PBF-ND/2127672

Use the filtering that's available and find the right part for the job. ebay is not the place to find parts. http://www.digikey.com/product-search/en?FV=fff40015%2Cfff8007d%2C1140050%2Cefc0005&k=n-channel+mosfet&mnonly=0&newproducts=0&ColumnSort=1000011&page=1&stock=1&pbfree=0&rohs=0&quantity=&ptm=0&fid=0&pageSize=25

One thing to watch out for - a lot of these parts are rated for high currents, but only for pulses. Use the column for continuous current as a filtering criteria. You may have to give these parts good heatsinking.

In my country there are no real distributors that can offer parts at that price. Does digikey send worldwide?

I have no attachments to ebay, but in most cases I plan to the future. So I can wait for 4weeks.

Just a quick comparison: 2N2222 transistor: 100pcs - $1.39 from ebay. 1pcs - $0.65 :'( so I usually order from ebay

I think digikey ships world wide. You can use their filtering to find a suitable part, even if you end up buying it elsewhere.

Great idea. I will surely use their filters :) shipping price for under 200$ only 60$ :D

eBay is great for buying common, simple parts. Resistors, capacitors, basic transistors, LEDs, microcontrollers, and stuff mounted on breakout boards? Ebay’s got it, for stunningly low prices.

For everything else, including beefy logic level transistors, you’re unlikely to find what you’re looking for there.
Digikey/Network14 aka Farnell when you need selection and/or professional supplier (both of those run a very tight ship, particularly digikey). Tayda electronics is somewhere in the middle, but imo closer to the ebay side.