PNDS / Marking codes / EF

Identify an unknown SMD part: marking code “EF”

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 10 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
BCV29	INFINEON	SOT-89	Public marking directory
BCV29	PHI	SOT89	Public marking directory
BCW66F	INFINEON	SOT-23	Public marking directory
BD4845FVE	ROHM ^*	VSOF-5	Public marking directory
BD4845G	ROHM ^*	SSOP-5	Public marking directory
MAZD082	PANASONIC ^*	—	Public marking directory
P6SMBJ120C	LITTLE ^*	DO-214AA	Public marking directory
R3112Q451A	RICOH ^*	SC-82AB	Public marking directory
RT9167-30CB	RICHTEK TECHNOLOGY, CORP.	SOT-23-5	Public marking directory
UNR31AM	PANASONIC ^*	—	Public marking directory
2SC5814-F	—	SC-59	Public marking directory
2SC5815-F	—	SC-70	Public marking directory
2SC5816-F	—	SC-75A	Public marking directory
2SC5817-F	—	—	Public marking directory
AP1701FTW	—	—	Public marking directory
AP1701FW	—	SOT-23-3L	Public marking directory
Cathode1	—	—	Public marking directory
MMSZ4715	—	SOD-123	Public marking directory
R1141Q151D	—	SOT-143R	Public marking directory
RD74LVC1G79WPE	—	—	Public marking directory
TS809CXF	—	SOT-23	Public marking directory
TV06B121KB	—	DO-214AA	Public marking directory
XC6127C25KNR	—	SSOT-24	Public marking directory
XC6127N26ENR	—	SSOT-24	Public marking directory
XC6223D251NR-G	—	SSOT-24	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 “E”

EK EV E0 E1 E2 E3 E4 E5 E6 E8

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.