Identify an unknown SMD part: marking code “F”

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 13 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
10V	FC	SOT-346	Public marking directory
1PS79SB10	NXP	SOD-523	Public marking directory
BAS20-02W	INFINEON	—	Public marking directory
BAS70-02L	INFINEON	—	Public marking directory
BZX79-C9V1	PHI	SOD27 (DO35)	Public marking directory
HMPP-3862	AGILENT	—	Public marking directory
HMPP-3865	AGILENT	—	Public marking directory
KV1831E	TOKO	—	Public marking directory
MAZS033	PANASONIC *	SC-79	Public marking directory
MAZS0330L	PANASONIC *	SC-79	Public marking directory
MRF927	MOT	SOT323	Public marking directory
RB521S-30	MCC	SOD-523	Public marking directory
UNR211W	PANASONIC *	SC-59 16ta - 3a Pan	Public marking directory
02P18	—	USP-6B	Public marking directory
09L	—	SOT-23	Public marking directory
09M	—	SOT-23	Public marking directory
09R	—	SOT-23	Public marking directory
09S	—	SOT-23	Public marking directory
09T	—	SOT-23	Public marking directory
10J	—	SOT-23	Public marking directory
10L	—	SC-59	Public marking directory
10M	—	SC-59	Public marking directory
10S	—	SOT-23	Public marking directory
10T	—	SOT-23	Public marking directory
7S02	—	SOT-23-5	Public marking directory

How we narrow this down

1. Package first — SOT-23 vs SOD-123 vs SC-59 eliminates most candidates immediately.
2. Pin count and body size — a 3-pin SOT-23 LDO cannot be a 6-pin dual transistor.
3. Marking style — laser-marked parts are usually newer production; ink marking often indicates older or second-source vendors.
4. Circuits around it — a part sitting on a rail with an inductor is a regulator, not a diode.
5. 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 “F”

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.