What 1A can be
1ABC846ANPN transistorSOT-23 · Nexperia · 65 V · 100 mA · hFE 110-220
Pins: 1=B 2=E 3=C
On the part, one more character can follow 1A: a date or factory code. datasheet
1APMBT3904NPN transistorSOT-23 · Nexperia · 40 V · 200 mA · hFE 100-300
Pins: 1=B 2=E 3=C
On the part, one more character can come before 1A: a factory code. datasheet
Package size
| Package | Also called | Body | Height |
|---|---|---|---|
| SOT-23 | TO-236AB, SOT-23-3 | 2.9 × 1.3 mm | 1 mm |
Nominal body size without the leads.
How to tell them apart
Look at the extra character: on the BC846A it follows the code (1A•), on the PMBT3904 it comes before it (•1A).
With the same package and code, look at how the part is used in the circuit and compare it with the ratings above.
Open the SMD identifier →Not sure it is this part? Enter the marking with the shape and size of the body: the identifier checks it against all 340 markings in the database.
Related parts and their markings
| Part | Marking | Type | Package |
|---|---|---|---|
| BC846 | 1D | NPN transistor | SOT-23 |
| BC846B | 1B | NPN transistor | SOT-23 |
| BC846BW | 1B | NPN transistor | SOT-323 |
Codes that look similar
Easy to mix up with 1A when the print is worn or a character is cut off:
Frequently asked questions
What is the pinout of SMD code 1A?
BC846A (SOT-23): 1=B 2=E 3=C. PMBT3904 (SOT-23): 1=B 2=E 3=C.
Marking codes checked against the makers’ datasheets; each part links to its own.