Does anyone here know of where I can find cheap thru hole vgs threshold of 1V, rds very very low so that it can be used as on or off switch to drive load, ids of 1.5A? Link please

 

vgs threshold of 1V

There are none. What gate voltages do you have available?

 

There are none. What gate voltages do you have available?

How come? My gate to source voltage is 3V or 0V. 3V nmos needs to be on and 0V nmos off.

 

Finding thru-hole parts is getting harder and harder every year, so the chance of finding a suitable such part goes down with time. There are lots of surface mount parts that have threshold voltages all around your 1 V target (but keep in mind that there can be a significant range of effective threshold voltages from part-to-part). Do searches on DigiKey or Mouser to explore what is available. Without knowing what, for you, constitutes "rds very very low", we can't help much. Similarly, without knowing what the max Vds is when off, we can't help too much.

 

Finding thru-hole parts is getting harder and harder every year, so the chance of finding a suitable such part goes down with time. There are lots of surface mount parts that have threshold voltages all around your 1 V target (but keep in mind that there can be a significant range of effective threshold voltages from part-to-part). Do searches on DigiKey or Mouser to explore what is available. Without knowing what, for you, constitutes "rds very very low", we can't help much. Similarly, without knowing what the max Vds is when off, we can't help too much.

How do I solder surface mount components in prefer board like this?

https://www.digikey.com/en/products...e=1&gbraid=0AAAAADrbLlhozHv6ho8PoIQF1UCwU1f1J

 

Here is the TN0702 from Supertex. Vgs(th) = 0.8V (typ), and rds(on) = 1.9Ω (typ). Is that good enough?
Next time try the Digikey search tool, it works pretty well. Quantity 1 price is $1.52 from Digikey. For 100 pieces it is $1.14

 

How do I solder surface mount components in prefer board like this?

Either by soldering legs to the SMD or buying an adapter board from AliX.

 

Either by soldering legs to the SMD or buying an adapter board from AliX.
View attachment 324988

Hiw can you considered soldering legs? You know how small they are? Its hard to solder legs manually?

Also what are the adapter boards?

 

Does anyone here know of where I can find cheap thru hole vgs threshold of 1V

With a 3V signal, you don't need a threshold voltage of 1V. IRLZ44N would likely work. Threshold voltage is 1-2V. On resistance with Vgs=4V is 40mΩ.

If you go surface mount, AO3400 has a threshold voltage of 0.65-1.45V, on resistance is 52mΩ at Vgs=2.5V.

I use this adapter:

EDIT: add datasheets

 

Hiw can you considered soldering legs? You know how small they are? Its hard to solder legs manually?

I would assume the SMD would be SOT23 or similar. Easy enough to tack on 24 or 22AWG wire to use for perf board through hole mounting. Wouldn't want to try it with 0403 resistors or caps but SOT23 isn't all that small. People do it all the time in a pinch when they have the SMD but not the through hole component. The only possible issue you may run into is not having a large surface contact solder pad to use as a heat sink. Sitting above the board on wire "stilts" does aid in cooling though. Just don't push the component very hard and give it plenty of current head room so it won't overheat. I posted a "typical" link for SMD to through hole adapters... Available from many sources and handy to keep on the shelf.

 

With a 3V signal, you don't need a threshold voltage of 1V. IRLZ44N would likely work. Threshold voltage is 1-2V. On resistance with Vgs=4V is 40mΩ.

If you go surface mount, AO3400 has a threshold voltage of 0.65-1.45V, on resistance is 52mΩ at Vgs=2.5V.

I use this adapter:
View attachment 324991

Wow thats very tiny. How did you solder that on the adapter? What kind of solder iron you used and solder?

 

Wow thats very tiny.

SC-89 is even smaller.

What kind of solder iron you used and solder?

I use a Weller W-TCP with a 1/32" conical tip (PTP7) with wire solder (0.032" or 0.015") or solder paste. I use an iron even with the solder paste.

The adapters cost $0.10 each the last time I bought them from AliExpress. The leadframes are hard to find and cost about $0.10 each (qty 100) when you can find them. I have 4 types available in this barter thread.

 

SC-89 is even smaller.

I use a Weller W-TCP with a 1/32" conical tip (PTP7) with wire solder (0.032" or 0.015") or solder paste. I use an iron even with the solder paste.

The adapters cost $0.10 each the last time I bought them from AliExpress. The leadframes are hard to find and cost about $0.10 each (qty 100) when you can find them. I have 4 types available in this barter thread.
View attachment 325031

What model iron you use?

 

What model iron you use?

The W-TCP uses the TCP-1 magnestat pencil iron:


I usually use a 700F tip.