I have an FQP30N06L logic level n-channel mosfet that works great with 3.3v and 5v controllersm but i really want to try the SMD version of an component with the same or greater specs.
I have been on Mouser and checked, but i really do not know what to look for exactly.
Can someone here just tell me what SMD mosfet n-channel logic level to choose?
Maybe DMN6017SK3
It is not so simple because you are also using the FQP30N06L at 3.3 volts which is out of the quoted spec., so you start having to look at the graphs in the data sheet.
You've said N-channel. Look for a very low RDS(on) (Ohms) at the gate voltage you are driving it at (say 5 volts)
Other than that, look at the maximum ratings to ensure you don't exceed these. Then other things like the package, price etc. etc.
I will add a few more things to filter for
Max Drain current
Max Vdss
Min Rds based on Vgs you need (3.3v to 5v). Vgs threshold is only where the mosfet conducts about 250 uA so you really want that to be a low voltage and should be ignored.
Package - research SMD for size and heat dissipation some calculations needed
Price - huge differences here
It’s a little complex but you can get good results researching this. Max drain current also depends on your Vgs and heat dissipation so the number they give you is only theoretical at best.
I personally like the Alpha Omega ones for logic level but again it all depends on your application.
Max drain current is irrelevant in fact - if you chose a device with a suitable on-resistance for the
heat-sinking you are providing, current will not be an issue - the limit is thermal almost always.
(Having said that if you are producing very high current pulses then check the max current).
Choose the device voltage about double the supply voltage, gives a good margin of safety including
for any ringing on switch-off. Don't go overboard, higher voltage devices have poorer on-resistance
all else being equal.
The key parameter is on-resistance - calculate the dissipation using this (power = current squared times
on-resistance) - that's the heat dissipation you'll need to deal with. Note the device power dissipation details in the datasheet - often this is given for no heatsink and for infinite heatsink - with a real heatsink you need to figure out the actual max power possible.
In fact first figure out the max on-resistance you'd be happy with, and filter devices by this. If you
need heatsinking it will allow somewhat more current for a particular device, but you'll need to provide
the heatsinking - another device might be better.
Go by the Vgs given in the on-resistance specification only. Nothing else matters. So if the
datasheet says something like "max Rds(on) = 0.05 ohms at Vgs=10V and 0.07 ohms at Vgs=4.5V"
then:
Only go by the max Rds(on) values and associated Vgs.
This is where the Mouser etc. product category search breaks down a bit because here you are actually looking for a combined parameter, that is RDS(on) which, in this application, should be as low as possible but it should be quoted at a Vgs of, in your case, 3.3volts or lower. You simply cannot enter this combination of parameters.
This was harder than I thought...
If there is someone here that can find a SMD mosfet with the same or better specs than FQP30N06L
I would really appreciate it.
I want to fold my lower lip over my head and force myself to swallow every time i se data sheets... I understand a little, but not enough to find a SMD mosfet with the same specs as FQP30N06L.
The FQP30N06L mosfet i found when i looked at one og Andreas Spiess (The guy with the swiss accent) videos on Youtube.
What is the supply voltage ?
What will be the maximum current you will need to switch ?
Consider these:
AO4484
AOD514
AOD4184
NDP6020
You weren’t happy with the DMN6017SK3 mentioned in post #1 ?
larryd:
What is the supply voltage ?
What will be the maximum current you will need to switch ?
Maximum voltage generally is about 12v. But it doesn't matter if it can withstand more volts either.
Current, i guess i need normally around 1-2 amp, but i wil also try some leds etc. so i thing as much current as possible.
The part numbers listed in post #7 would fit the bill.
larryd:
Consider these:AO4484
AOD514
AOD4184
NDP6020
What is the difference of theese, and witch should i choose?
I forgot to mention that the transistor must fit the holes in a standard veroboard.
Bjerknez:
I forgot to mention that the transistor must fit the holes in a standard veroboard.
You the want a mosfet in an SMD (surface mount) package that is “through the hole” compatible. Good luck with a search for that. If the FQP30N06L works for you, then continue use that.
6v6gt:
You the want a mosfet in an SMD (surface mount) package that is “through the hole” compatible. Good luck with a search for that. If the FQP30N06L works for you, then continue use that.
I meant that the SMD component must fit between the holes. The legs of the component must reatch between holes.
Now you’re just getting silly.. why not just use a thru hole...
wolframore:
Now you’re just getting silly.. why not just use a thru hole...
Because an SMD component takes up less space?
Veroboards are made for thruhole. Research mosfet packages and maybe you can find one that works.l. The pads might or might not line up. If you were designing a PCB you make the pads what ever size you need with the pins matching all your necessary connections. The requirements seem unreasonable to me.
If you look at the data sheets you will see they all meet your criteria.
i.e. 12v operation, 2amps.
6v6gt:
This is where the Mouser etc. product category search breaks down a bit because here you are actually looking for a combined parameter, that is RDS(on) which, in this application, should be as low as possible but it should be quoted at a Vgs of, in your case, 3.3volts or lower. You simply cannot enter this combination of parameters.
Farnell's search facility allows this, select the Vgs test voltage, sort by on resistance. Just cause you
search on their site doesn't mean you have to buy from them(!)