Please recommend me some SMD transistors for arduino projects  - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: September 14, 2021, 07:38:14 pm
content: I want to buy few SMD transistors for arduino project, its not specific to drive a particular thing but just to keep in my stock because it takes 15/30 days to deliver, as I'm living in a remote area.SMD NPN transistor for driving with 3.3v/5v can handle 200mA to 800mA, up to 24vSMD NPN/N Channel transistor/MOSFET for driving with 3.3v/5v can handle 1A, 1.5 to 3A, up to 24v(obviously could be two three types to manage this range.)Is there some web page to find transistor by putting some parameters?

author: westfw
author_rank: Super Contributor
timestamp: September 15, 2021, 02:36:01 am
content: What sized smd package are you thinking?800mA is a lot for an sot-23 sized npn bjt, I think, if you’re talking actual use.Probably hard to go wrong with an mmbt2222a…

author: BlackICE
author_rank: Regular Contributor
timestamp: September 15, 2021, 02:45:42 am
content: I don't think you've given enough parameters. Do you just want to use this as a power switching application where frequency doesn't matter, or do you want to switch many times for a second and you worried about heat dissipation efficiency?

author: sairfan1
author_rank: Frequent Contributor
timestamp: September 15, 2021, 03:32:53 am
content: I want SOT-23 package for sure not very small package,Mostly switching relay, PWM for LEDs, Neon, MotorsIts for generic use so that i have reasonable stock with me, its not for some professional project, that means i can use a 2Am MOSFET where 1Am MOSFET is enough

author: perieanuo
author_rank: Frequent Contributor
timestamp: September 15, 2021, 09:06:06 am
content: any major supplier has transistor selection, you can choose from farnell for examplefinally, choose some rohs and ready for new designs and cheap and stocked in large quantities, nothing special herepackage/voltage/current is up to your app, i used myself some mmbt2222 for small loads, mmbt4401, mun2211, 2n7002e, ntr4101p, bc846pn ...https://canada.newark.com/c/semiconductors-discretes/transistors?ICID=I-HP-PC-SEMICONDUCTORS_TRANSISTORS-MAY20-WF1980967

author: Whales
author_rank: Super Contributor
timestamp: September 15, 2021, 09:08:08 am
content: 2n7002 is a very common mosfet to get in a SOT-23 package, I make lots of experimental circuits with them.

author: David Hess
author_rank: Super Contributor
timestamp: September 15, 2021, 11:21:37 am
content: Quote from: sairfan1 on September 14, 2021, 07:38:14 pmBipolar transistor current gain falls as it approaches its maximum current so usually a part with a significantly higher current rating is used just to have a higher current gain.

author: Kleinstein
author_rank: Super Contributor
timestamp: September 15, 2021, 11:39:00 am
content: Most parts source have some sort of slection tool. So you could look among the lowest cost BJTs / FETs they have, at least for the lower currents.It very much depends on the source for the parts, which they actually offer.The maximum current rating can be a bit optimistic with cooling. The practical useful current may be lower than the transistor rating.For the higher currents one may consider a larger case like sot223 (e.g. BCP56/BCP53).

author: cemelec
author_rank: Contributor
timestamp: September 15, 2021, 02:08:20 pm
content: Some time ago I bought a set of different transistors from Aliexpress similar to this:https://www.aliexpress.com/item/32301950979.html?spm=a2g0s.9042311.0.0.27424c4dXrQ5mKThere's a reasonable selection of various bipolar & FET transistors in the kit I bought, and I got it just so as I would have some in just in case. Might suit your requirements, its super cheap and it saves you a lot of time buying individually.I partially filled in a spreadsheet with the main characteristics (some of them) so you can preselect something then find the main datasheet.If you search on AliExpress I'm sure you would find something

author: bingo600
author_rank: Super Contributor
timestamp: September 15, 2021, 04:18:32 pm
content: While i'm certainly not an EE , i was bitten by Vgs(th) when using 7002's on 3.3vI went to bss138 , for 3.3v small signal (200mA) , and as mentioned there are prob. newer/better choices.I also bought some A3400/A3401 FET's.As far as i can see they should be usable on 3.3v too.A3400https://www.aliexpress.com/item/33006799422.htmlA3401https://www.aliexpress.com/item/33006783529.htmlI hope they're not made of "Chinesium" , but haven't used them yet./Bingo