PNDS / Marking codes / BM

Identify an unknown SMD part: marking code “BM”

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 19 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
BCP55-16	PHI	SOT-223	Public marking directory
BCX55-16	NXP	SOT-89	Public marking directory
BCX55-16	PHI	SC-62/SOT89	Public marking directory
BCX70G	MCC	SOT-23	Public marking directory
BD4731G	ROHM ^*	—	Public marking directory
BSS63L	MOT	SOT23	Public marking directory
BZT52H-C13	NXP	SOD123F	Public marking directory
BZX399-C13	PHI	SOD-323	Public marking directory
BZX399-C13	PHI	SC-76/SOD323	Public marking directory
BZX399C13	NXP	SOD323	Public marking directory
MAX821PUS-T	MAX	SOT-143	Public marking directory
MMBZ5250B	FSC	SOT-23 16dc - 3a Lge	Public marking directory
P6SMBJ15AC	LITTLE ^*	DO-214AA	Public marking directory
R1112N311A	RICOH ^*	SOT-23-5	Public marking directory
R3112Q111C	RICOH ^*	SC-82AB	Public marking directory
R5421N163C	RICOH ^*	SOT-23-6	Public marking directory
SMF15A	ON	DO-219AB	Public marking directory
UDZ15B	DIODES	SOD-323	Public marking directory
UDZ5V1B	DIODES	—	Public marking directory
2SB1325	—	—	Public marking directory
CD214B-T15CA	—	DO-214AA	Public marking directory
GS6333UR25D3	—	SOT-23	Public marking directory
MMSZ4685	—	SOD-123	Public marking directory
P4SMA24A	—	DO-214AC	Public marking directory
P4SMAJ15A	—	DO-214AC	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 “B”

B1 B2 B3 B4 B5 B6 B7 B8 B9 BA

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.