PNDS / Marking codes / AX

Identify an unknown SMD part: marking code “AX”

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 8 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
BCX70JR	ITT	SOT-23	Public marking directory
BCX70RJ	TELEFUNKEN	SOT-23	Public marking directory
IMP812REUS-T	IMP	SOT-143	Public marking directory
MAX812R	MAX ^*	SOT-143	Public marking directory
MAX812RUS	MAX ^*	SOT-143	Public marking directory
MMBZ5238B	FSC	SOT-23 16dc - 3a Lge	Public marking directory
P6SMBJ10AC	LITTLE ^*	DO-214AA	Public marking directory
SMF10A	ON	DO-219AB	Public marking directory
50A02CH	—	CPH3 16ta - 3a San	Public marking directory
AT1201-50X	—	SOT-23-5	Public marking directory
CD214B-T10CA	—	DO-214AA	Public marking directory
GS6333UR21D2	—	SOT-23	Public marking directory
P4SMA15A	—	DO-214AC	Public marking directory
P4SMAJ10A	—	DO-214AC	Public marking directory
PT7M7812TTB	—	SOT-143	Public marking directory
PT7M7812TTBE	—	SOT-143	Public marking directory
RT9809-49CV	—	SOT-23 16vdc VD7 3a Rct	Public marking directory
SiP6333R21D2	—	SOT-23	Public marking directory
SiP825ZEU	—	SOT-23-5	Public marking directory
TV04A100J	—	DO-214AC	Public marking directory
TV06B100JB	—	DO-214AA	Public marking directory
XC6127C49FNR	—	SSOT-24	Public marking directory
XC6127N50ANR	—	SSOT-24	Public marking directory
XC6221A28BN	—	SSOT-24 26vn VR4 5a Tor	Public marking directory
XC6221A28BNR	—	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.