PNDS / Marking codes / C1

Identify an unknown SMD part: marking code “C1”

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 25 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
1SS352	TOS	SOD-323	Public marking directory
1SS368	TOS	SOD-323	Public marking directory
1SS387	TOS	SOD-323	Public marking directory
BCW29	PHI	SOT-23	Public marking directory
BFQ51C	PHI	SOT173	Public marking directory
BZT52H-C47	NXP	SOD123F	Public marking directory
DMC2004VK	DIODES	—	Public marking directory
HSMS-2821	HP	SOT23	Public marking directory
LM4899ITL	NSC	BGA-9	Public marking directory
LM4899ITLX	NSC ^*	BGA-9	Public marking directory
MMBZ5221B	DIODES	SOT-23	Public marking directory
MMBZ5221BW	DIODES	SOT-323	Public marking directory
MMSZ5221B	DIODES	SOD-123	Public marking directory
MMSZ5221BS	DIODES	SOD-323	Public marking directory
MMSZ5221BS	DIODES	—	Public marking directory
MMSZ5222B	MCC	SOD-123	Public marking directory
MMSZ5223B	DIODES	—	Public marking directory
MMXZ5221B	MCC	SOD-323	Public marking directory
R3111N212A	RICOH ^*	SOT-23	Public marking directory
R3113D311A	RICOH ^*	—	Public marking directory
R3114Q281A	RICOH ^*	SC-82AB	Public marking directory
RN1902AFS	TOS ^*	—	Public marking directory
SST111	SILICONIX-VISHAY	SOT-23	Public marking directory
TC1054-2.5VCT713	MIC ^*	SOT-23-5	Public marking directory
TC4S11F	TOS	SOT-353	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 “C”

C0 C2 C3 C4 C5 C6 C7 C8 C9 CA

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.