PNDS / Marking codes / A1

Identify an unknown SMD part: marking code “A1”

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.

25 candidates 14 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
1SS272	TOS	SOT-143	Public marking directory
1SS308	TOS	SOT-23-5	Public marking directory
1SS382	TOS	SOT-343	Public marking directory
BA591	PHI	SOD-323	Public marking directory
BAW56	FSC	SOT-23	Public marking directory
BAW56T	PHI	SC-75	Public marking directory
BAW56T	PHI	SC-75/SOT416	Public marking directory
BAW56W	PHI	SOT-323	Public marking directory
BAW56W	PHI	SC-70/SOT323	Public marking directory
HSMS-2801	HP	—	Public marking directory
MC2831	MOT ^*	SC-59	Public marking directory
MMSZ10	ON ^*	SOD-123	Public marking directory
R3114Q081A	RICOH ^*	SC-82AB	Public marking directory
TC1014-2.5VRX	MIC ^*	SOT-23-5	Public marking directory
2SJ243	—	SC-70	Public marking directory
BAS240	—	SOD-110	Public marking directory
BAW56L	—	SOT-23	Public marking directory
BAW56PT	—	SOT-23 16df - 3a Chm	Public marking directory
BAW56TPT	—	SOT-416 16df - 3a Chm	Public marking directory
BGA2001	—	SOT-143	Public marking directory
BZX884-B2V4	—	SOD-882	Public marking directory
CHP202KPT	—	SC-59 16df - 3a Chm	Public marking directory
CHP222PT	—	SOT-416 16df - 3a Chm	Public marking directory
D70G.05T1	—	SOT-89	Public marking directory
DSE015	—	MCP 16eb - 3a San	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 A2 A3 A4 A5 A6 A7 A8 A9

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.