PNDS / Marking codes / CK

Identify an unknown SMD part: marking code “CK”

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
BCX71JR	FERRANTI	SOT-23R	Public marking directory
BCX71KR	FERRANTI	SOT-23	Public marking directory
BCX71RK	SIEMENS	SOT-23	Public marking directory
BH15LB1WG	ROHM ^*	SSOP-5	Public marking directory
BH15LB1WHFV	ROHM ^*	—	Public marking directory
HSMS-282K	AGILENT	SOT-363	Public marking directory
MAX6314US28D1-T	MAX ^*	SOT-143	Public marking directory
MMBZ4684	VISHAY ^*	SOT-23	Public marking directory
MMSZ4684	FSC	SOD-123	Public marking directory
P4SMAJ30A	DIOTEC	DO-214AC	Public marking directory
P6SMBJ30AC	LITTLE ^*	DO-214AA	Public marking directory
R3112Q291A	RICOH ^*	SC-82AB	Public marking directory
RN5RT49AA	RICOH ^*	SOT-23-5	Public marking directory
SMF30A	ON	DO-219AB	Public marking directory
UNR31A4	PANASONIC ^*	—	Public marking directory
15C02MH	—	MCPH3 18ta - 3a San	Public marking directory
2SD999-K	—	SOT-89	Public marking directory
AP130-25TW	—	—	Public marking directory
AP130-25W	—	SOT-23	Public marking directory
AP130-25Y	—	SOT-89	Public marking directory
CD214B-T30CA	—	DO-214AA	Public marking directory
CPH3210	—	—	Public marking directory
ELM99491B	—	SOT-89	Public marking directory
GS6332UR22D2	—	SOT-23	Public marking directory
MMSZ4700	—	SOD-123	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 C1 C2 C3 C4 C5 C6 C7 C8 C9

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.