PNDS / Marking codes / D3

Identify an unknown SMD part: marking code “D3”

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 16 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
1SS187	TOS	SC-59	Public marking directory
AZ23C3V3	DIODES	SOT-23	Public marking directory
BCW33	NXP	SOT-23	Public marking directory
KV1735R	TOKO	SOT-23C-3	Public marking directory
MMBZ5228B	FSC	SOT-23	Public marking directory
MMBZ5228BW	DIODES	SOT-323	Public marking directory
MMSZ5228B	FSC	SOD-123	Public marking directory
R3111N332A	RICOH ^*	SOT-23	Public marking directory
R3113D431A	RICOH ^*	—	Public marking directory
R3114Q401A	RICOH ^*	SC-82AB	Public marking directory
RN2904AFS	TOS ^*	—	Public marking directory
RN5VD33AA	RICOH ^*	SOT-23-5	Public marking directory
SST213	SILICONIX-VISHAY	SOT-143	Public marking directory
TC1055-3.0VCT713	MIC	SOT-23-5	Public marking directory
TC54VC3302ECB	MIC ^*	SOT-23	Public marking directory
TC54VC3302MB	MIC ^*	SOT-89	Public marking directory
2SC5277-3	—	SMCP	Public marking directory
3T080AB	—	DO-214AA	Public marking directory
AP131-44TW	—	—	Public marking directory
AP131-44W	—	SOT-23-5L	Public marking directory
AP131-44Y	—	SOT-89-5L	Public marking directory
AX1110R25	—	SOT-23L 16vl VR1 3b Axl	Public marking directory
BAP65-03	—	SOD-323	Public marking directory
BZX884-C20	—	SOD-882	Public marking directory
ELM9733NAB	—	SOT-89	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 “D”

D0 D1 D2 D4 D5 D6 D7 D8 D9 DA

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.