PNDS / Marking codes / AB

Identify an unknown SMD part: marking code “AB”

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 13 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
BAR50-02L	INFINEON	—	Public marking directory
BCW60B	PHI	SOT-23	Public marking directory
BCX51-6	INFINEON	SOT-89	Public marking directory
BZX884-B6V2	NXP	SOD-882	Public marking directory
MAX6314US49D1-T	MAX ^*	SOT-143	Public marking directory
MMBD4448HTS	DIODES	SOT-523	Public marking directory
MMBD4448HTW	DIODES	—	Public marking directory
MMBZ5226B	FSC	SOT-23 16dc - 3a Lge	Public marking directory
MMSZ5222B	MCC	SOD-123	Public marking directory
PI74ST1G126CX	PERICOM ^*	SC-70-5	Public marking directory
PI74ST1G126TX	PERICOM ^*	SOT-23-5	Public marking directory
RN5RT21AA	RICOH ^*	SOT-23-5	Public marking directory
ZMV830A	ZETEX	SOD-323	Public marking directory
2SD1101B	—	SC-59A 16ta - 3a Ren	Public marking directory
2SD1366-AB	—	SOT-89	Public marking directory
74AHC1G02	—	SOT-353	Public marking directory
AP431IAY	—	SOT-89-3L	Public marking directory
BCX51-06	—	SOT-89	Public marking directory
ELM99211B	—	SOT-89	Public marking directory
MAZU200-H	—	SOT-346	Public marking directory
RP130Q131A	—	SC-82AB	Public marking directory
RT9161-29CV	—	SOT-23	Public marking directory
RT9161-38CX	—	SOT-89	Public marking directory
SiP823MEU	—	SOT-23-5	Public marking directory
XC6127C17FNR	—	SSOT-24	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.