PNDS / Marking codes / A

Identify an unknown SMD part: marking code “A”

Packages rarely print the full part number. The marking below is shared by several part numbers — use the package, pin count and the manufacturer family together to narrow it down, then confirm against the datasheet.

18 candidates 12 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
1SS355	MCC	SOD-323	Public marking directory
1SS400	MCC	SOD-523	Public marking directory
1SS404	MCC	SOD-323	Public marking directory
BA892	INFINEON	—	Public marking directory
BA892-02V	INFINEON	SC-79	Public marking directory
BAR50-02V	INFINEON	SC-79	Public marking directory
MAV-11SM	MCL MINICIRCUITS	—	Public marking directory
MBRX02530	MCC	SOD-323	Public marking directory
MRF947	MOT	SOT-323	Public marking directory
MRF947T1	MOT	SOT-323	Public marking directory
UNRL111	PANASONIC ^*	ML4 31tm - 2b Pan	Public marking directory
UNRL211	PANASONIC ^*	ML4 31tm - 2b Pan	Public marking directory
3SK301	—	SOT-143	Public marking directory
3SK305	—	SOT-343	Public marking directory
EP05Q04	—	SOD-123	Public marking directory
GBLC05I	—	SOD-323	Public marking directory
SB01-05CP	—	SOT-23	Public marking directory
SB01-05Q	—	—	Public marking directory

How we narrow this down

Package first — SOT-23 vs SOD-123 vs SC-59 eliminates most candidates immediately.
Pin count and body size — a 3-pin SOT-23 LDO cannot be a 6-pin dual transistor.
Marking style — laser-marked parts are usually newer production; ink marking often indicates older or second-source vendors.
Circuits around it — a part sitting on a rail with an inductor is a regulator, not a diode.
Datasheet check — every credible candidate lists its marking scheme in the “marking information” section.

FAQ

Same code, several parts — which one do I actually have? Compare package + pin count + surrounding circuit; if it still fits two parts, request a sample verification before production.
Can I substitute between the candidates? No — the same marking may sit on electrically different parts. Always match the electrical spec sheet, not just the marking.
Where do these mappings come from? Public SMD marking directories and historical stock tables; each row keeps its source so you can trace it.

Other codes starting with “A”

AL AH-16 A1 A2 A3 A4 A5 A6 A7 A8

Still not sure what the part is?

Send the code, package and a photo through the BOM hub — our engineers cross-check it against datasheets and sourcing records.

How these mappings are compiled: public SMD marking directories plus our own stock records. Each row keeps its original reference internally, so any mapping can be traced on request. ^* Manufacturer derived from the part-number family (some directory entries carry no manufacturer) — treat it as a lead, not a datasheet fact. Markings are indicative only — confirm with the physical batch marking and the original datasheet before ordering.