I'm looking to PWM an LED strip with an ESP8266 (3.3 V PWM signal) with the following characteristics:

  • Red channel: 12 V, 300 mA
  • Green channel: 12 V, 250 mA
  • Blue channel: 12 V, 250 mA

As I understand it, a MOSFET is best suited for this task, so I've been reading as much as I can to understand which specific parts might be suitable. Ideally I would like a through-hole component, but these seem harder to find, so I've got some surface-mount ones in the list too. This is what I've come up with:

  • BSS816NW
    • ❓ Only slight concern is that graph 5 doesn't show a \$V_{gs}\$ greater than 2.5 V. Am I missing something here that would make this unsuitable?
    • πŸ‘Ž It's SMT, which isn't my first choice.
    • πŸ‘ Low \$R_{DS(on)}\$ resistance, which is good.
  • TN0702
    • πŸ‘Ž It has a higher \$R_{DS(on)}\$ resistance.
    • πŸ‘ It's THT!
    • πŸ‘Ž It's expensive!
  • FDN337N
    • πŸ‘Ž It's SMT.
    • πŸ‘ Low \$R_{DS(on)}\$ resistance.

I'm leaning towards the TN0702 as it meets my THT criteria, but could use one of the others if necessary. So my question is: Are any/all of these components suitable for the job? I've not used MOSFETs before and am quite inexperienced with electronics, so would be grateful of any advice.


1 Answer 1


Yes they will work. The through-hole one will dissipate 1/4 to 1/3 W. The two SMTs are much better electronically.

  • \$\begingroup\$ Thanks @RussellH. Out of interest, where did you see the 1/4 - 1/4 W dissipation? I can only see the 1 W mentioned at the top of the second page. \$\endgroup\$
    – OdinX
    Sep 12, 2022 at 17:35
  • 1
    \$\begingroup\$ Used a calculation based on the current you intend to use and the on resistance. The on resistance for the SMTs is a factor of ten lower. \$\endgroup\$
    – RussellH
    Sep 12, 2022 at 17:40
  • \$\begingroup\$ Gottcha, thanks! \$\endgroup\$
    – OdinX
    Sep 12, 2022 at 17:43

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