Help ID Surface Mount Transistor/FET

[Frayn]

SOT-23 type package. Only markings 1C9I on top.
Any ideas.

Thank you

 

[Frayn]

Ok....this is what I've found so far.....

Could it be one of these three....

1C FMMT-A20 Zet N SOT23 MPSA20

1C MMBTA20L Mot N SOT23 MPS3904

1C IRLML6302 IR F SOT23 p-ch mosfet 20V 0.6A

I can take it out of the circuit and test it for the a NPN transitor with a meter.......any other tips? That would narrow it down a bit more....

Thanmk you

 

[Frayn]

Ok, I think I got it.

Doesn't test as a NPN transistotr.

1C IRLML6302 IR F SOT23 p-ch mosfet 20V 0.6A

Anyone know if this is normally on or normally off. What do they call it "depletion" or "enhancement" ?

 

[zappedagain]

The IRLML6302 data sheet shows it is a MOSFET, so it is normally off (enhancement). JFETs are depletion mode devices that are normally on.

 

[Fenda]

Hi Frayn
just as zappedagain said ,it is normally off as you can see the broken line in the symbol in the datasheet(if you got),that means we need to add a voltage between the gate and the source,so that the drain and source would be connected ,which would make the circuit work. This is why it is called "enhancement".
while for "depletion",that means it is normally on(drain and source connected),it is caused by its own inner materials (the isolating SiO2 with highly doped to make "on"),while sometimes we want it off ,so we add a negative voltage between gate and source to make it off.this is why we call it "depletion".

We are always available to help each other.