Author Topic: Logic Level MOSFET and Search woe  (Read 3991 times)

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Offline The Magic RabbitTopic starter

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Logic Level MOSFET and Search woe
« on: September 28, 2015, 06:29:36 pm »
I'm getting increasingly frustrated with the hopeless search facilities on most electronics suppliers websites. Where is the facility to enter basic search terms!?!?

I want logic gate level, through hole, MOSFETs, the cheaper the better, that can handle half an all of so.

Go on any site, and you have to specify the exact gate voltage... Well obviously that's BETWEEN two values! Try selecting the range and you get "too many filters" or some equally unhelpful nonsense. Anything .5A or over is fine... but no, you have to highlight 0.5,0.6,0.7,0.8,1.1.1,1.15,1.25,2 etc. etc.  Aaaargh!

How do you guys ever find what you need!?!??!? Is there since secret masonic handshake I'm not aware of that unlocks a common sense feature!?!?

2 hours of smacking my head against a wall with this crap and I've given up for today. I think I'd do better just phoning the manufacturers... international calls but at least I met get a straight answer.

Urgh.


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Offline suicidaleggroll

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Re: Logic Level MOSFET and Search woe
« Reply #1 on: September 28, 2015, 07:37:06 pm »
Anything .5A or over is fine... but no, you have to highlight 0.5,0.6,0.7,0.8,1.1.1,1.15,1.25,2 etc. etc.  Aaaargh!

1) Click on the low value
2) Hold the shift key
3) Click on the high value
4) ?
5) Profit!

You're making this out to be a much bigger deal than it is.  Or are you using some stupid touch-based device where you have to click every single entry to do your searching?

As for the "too many filters" error, just do your filtering in a different order.  Start with the easiest and/or most restrictive parameter(s) to knock you down from a million matches to a couple thousand, then you shouldn't have any trouble applying the other filters.
« Last Edit: September 28, 2015, 07:40:46 pm by suicidaleggroll »
 

Offline Howardlong

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Re: Logic Level MOSFET and Search woe
« Reply #2 on: September 28, 2015, 07:55:17 pm »
Through hole isn't great for choice on small form factor logic level MOSFETs particularly P channel.

I gave up, if I need to breadboard I use a SOT-23 or other surface mount device on a DIP breakout board. I keep a few ready to go in this state for prototyping.
 

Offline The Magic RabbitTopic starter

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Re: Logic Level MOSFET and Search woe
« Reply #3 on: September 28, 2015, 08:04:28 pm »
Clicking every entry isn't the issue (on a touch device you can often do Yap and hold instead of shift click) but every site I have done that on so far has then complained there are too many filters, and won't do the search. That includes the big three I'm aware of - RS, Mouser and Digikey.

It seems as if every selected value counts as a filter, hence if your high to low selection includes a load of values you hit the filter limit very very quickly.

Physical size isn't too much of an issue, it's cost I want to keep down since I'll need probably around 30 or so on this project. I have a restrictive 50mm width for the board, but I've got almost 1m length available in the enclosure (it's a strip).

I'm not fussy whether they're P or N really. N would be easier, but can easily adapt the wiring if P channel is cheaper.

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Offline KL27x

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Re: Logic Level MOSFET and Search woe
« Reply #4 on: September 28, 2015, 08:07:02 pm »
Quote
Through hole isn't great for choice on small form factor logic level MOSFETs particularly P channel.
I'm the same way. I have T0-92 dyslexia. But for a project that takes 30+, I will take the time to figure it out, if the longer leads help in construction.
 

Offline suicidaleggroll

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Re: Logic Level MOSFET and Search woe
« Reply #5 on: September 28, 2015, 08:17:57 pm »
every site I have done that on so far has then complained there are too many filters, and won't do the search. That includes the big three I'm aware of - RS, Mouser and Digikey.

It seems as if every selected value counts as a filter, hence if your high to low selection includes a load of values you hit the filter limit very very quickly.

Start with the restrictive filters first, and only do one at a time.

In this case, start with your desired package, that'll be just a few filters and will knock out a huge chunk of the results.  Then apply the filter, let the page re-load, and move to the next one, maybe Vgs(th).  Pick your range, apply that filter, re-load the page, and then move onto say Rds(on).  With each applied filter, the number of choices for the other filters will drop dramatically, so you won't hit the limit on the number of filters so easily.

From the sound of it you're trying to enter ALL of your parameters at once, and yes that will cause problems.  Just do your filtering in stages and start with the easiest/most restrictive one to knock out the majority of results right out of the gate.
« Last Edit: September 28, 2015, 08:26:43 pm by suicidaleggroll »
 

Offline The Magic RabbitTopic starter

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Re: Logic Level MOSFET and Search woe
« Reply #6 on: September 28, 2015, 08:48:22 pm »
Yes, I'm trying to do them all at once... just seemed common sense to do so.

Ended up using the IR website in the end, writing down a list of part numbers, then looking them up one by one. I think the IRLU024NPBF-ND is the cheapest. I don't know what an I-Pak is but the drawing of the package seems like it is a sensible size.

Fingers crossed?

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Offline ConKbot

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Re: Logic Level MOSFET and Search woe
« Reply #7 on: September 28, 2015, 11:22:52 pm »
“Too many filters " sounds like mouser. My usual search, for a mosfet would go:
Stocked (gets rid of a ton )
Surface mount (or through hole if that's your thing)
Cut tape (don't need to see the same thing 3 times for digireel/mousereel and whole reel too, tube and bulk if you're doing TH)
n or p channel
Pick a wide Vds range ( no point in a 300v mosfet if you only need 10v)

And then drill down from there.


 

Offline BloodyCactus

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Re: Logic Level MOSFET and Search woe
« Reply #8 on: September 29, 2015, 06:24:52 pm »
i always fall back onto the same old parts I've used before, things like IRL520/IRL530 for logic level mosfet

mouser search does drive me crazy time to time
-- Aussie living in the USA --
 

Offline The Magic RabbitTopic starter

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Re: Logic Level MOSFET and Search woe
« Reply #9 on: September 30, 2015, 11:22:28 pm »
IRL520 Is the only one I've used so far, but at over £1 each of would make my project horribly expensive!

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Offline FrankT

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Re: Logic Level MOSFET and Search woe
« Reply #10 on: September 30, 2015, 11:31:40 pm »
I found the manufacturer's websites are usually better.  They usually give you Rds(on) at different gate voltage levels. 

Obviously you restricted to individual manufacturers, but it is usually a good starting point.
 

Offline edavid

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Re: Logic Level MOSFET and Search woe
« Reply #11 on: September 30, 2015, 11:51:14 pm »
I agree, distributor websites are terrible.

Have you looked at the NTD3055L?

http://www.findchips.com/search/ntd3055l
 

Offline m12lrpv

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Re: Logic Level MOSFET and Search woe
« Reply #12 on: October 01, 2015, 12:18:53 am »
I feel your pain.
Few of the distributor websites allow you to filter effectively for logic level mosfets.

One day you'll just need to sit down and go through the datasheets for a stack of them and come up with a list of standard parts that will work for you. That's what I did.

I now stick with the following because it's to hard to search for anything better.
N-Channel
FQP13N06L - through hole
bss138 - smd

P-Channel
NDP6020P - through hole
NDS332P - smd
 

Offline JuKu

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Re: Logic Level MOSFET and Search woe
« Reply #13 on: October 01, 2015, 10:38:33 am »
My "goto" logic level FET is STD30NF06L.
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