PNDS / Marking codes / 1C

Identify an unknown SMD part: marking code “1C”

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 15 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
BC847BT	MCC	SOT-523	Public marking directory
BU4343F	ROHM ^*	SOP-4	Public marking directory
BU4343FWE	ROHM ^*	VSOF-5	Public marking directory
BU4343G	ROHM ^*	SSOP-5	Public marking directory
FMMT-A20	FERRANTI	SOT23	Public marking directory
IRLML6302	IR	SOT-23	Public marking directory
KST20	FSC	SOT-23	Public marking directory
MM5Z51V	FSC	SOD-523	Public marking directory
MMBTA20	NSC	SOT-23	Public marking directory
MMBTA20L	MOT	SOT23	Public marking directory
R3111N211A	RICOH ^*	SOT-23-5	Public marking directory
RH5RL31AA	RICOH ^*	SOT-89	Public marking directory
RN5RL31AA	RICOH ^*	SOT-23-5	Public marking directory
RQ5RW18BA	RICOH ^*	SOT-143R	Public marking directory
UNRF2AL	PANASONIC ^*	ML3 22ta - 2b Pan	Public marking directory
BC846C	—	SOT-23	Public marking directory
FMMTA20	—	SOT-23	Public marking directory
GBLC18C	—	SOD-323	Public marking directory
MM3Z2V4	—	SOD-323	Public marking directory
MM3Z51V	—	SOD-323	Public marking directory
R1161D211A	—	—	Public marking directory
R3131N31EC	—	SOT-23	Public marking directory
R3132Q22EA	—	SOT-143	Public marking directory
R5326N003A	—	SOT-23-6	Public marking directory
RN5VD21CA	—	SOT-23-5	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 “1”

10 11 12 13 14 15 16 18 1A 1B

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.