FET identification?

[andrewbostaph]

Hi everyone
                 Anyone know what FET this might be? Appears to be SOT-23 in size. Most likely an NPN and pin 2 is connected to GND. After a search online looking at SMD codes etc etc found nothing.

Cheers!

[frozenfrogz]

1A on SOT-23 would point towards NPN transistor.
http://www.s-manuals.com/smd/1a
http://www.sphere.bc.ca/download/smd-codebook.pdf

However, exclamation mark does not ring a bell.

You might be better of with a schematic to get the right specs in case this needs to be replaced.

[Simon]

Very difficult. This is the downside to SMD you will never know what it is unless it is a well known part or the number is a give away.

[andrewbostaph]

Since FET 1 appears to be an IRLML6401 according to some SMD codes online FET 2 maybe an IRLML2402 but the datasheets show something a little different. The exclamation mark has got me stumped.

[frozenfrogz]

Also this:
https://www.fairchildsemi.com.cn/Assets/-topmark/pinOne.ssi

Where the exclamation point marks pin 1 and the dashes somehow represent date codes. (?)

1A V does not ring a bell still.

Edit: The marking might very well be just "1A".
"V" and the Cyrillic looking "г" »Ghe« maybe are some manufacturer IDs?

The date code from the dashes above would read 101 and 100 representing 5 and 4, so I would guess 2005 and 2004 - just to get that out of the equation

If you can share more info on the actual circuit it sits in, we might be better of just selecting a proper part for the circuit, than blindly poking at those markings.

[andrewbostaph]

The "V" and "г" is probably the date of manufacture. The 2 lines above the A and V will also indicate something else.

[andrewbostaph]

Interesting markings from that link!

[Jwillis]

SOT (small outline transistor) 23    1A  is a BC846A or equivalent like BC846AT,BC546A,2N3904 if its Philips, Motorola or Zetex . Intentional rectifier 1A is a  n ch mosfet 20V 0.9A  IRLML2402

The actual dimensions of the package makes a difference as well  SOT 23 ,SOT 323 ,SOT 416 ,SC 59 ,SC 70 and SC 90 like very much alike but  have varying dimensions. But The 1A comes in SOT 23 ,SOT 416 and SOT 323

[andrewbostaph]

Turns out that its a Fairchild MMBT3904. Google "Fairchild sot23 markings" click on images and you will see that other components also use the "!" before the code marking The line in the "!" indicates the factory that manufactured the component and the dot underneath indicates PIN 1. https://www.fairchildsemi.com.cn/Assets/-topmark/pinOne.ssi