PNDS / Marking codes / L4

Identify an unknown SMD part: marking code “L4”

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
2SC1623-L4	MCC	SOT-23	Public marking directory
2SC2812-4	TOS ^*	CPA 16ta - 3a San	Public marking directory
2SC2812-L4	TOS ^*	—	Public marking directory
2SC4177-4	NEC ^*	SOT-323	Public marking directory
BAT254	PHI	SOD-110	Public marking directory
BAT254	PHI	SOD110	Public marking directory
BAT54	FSC	SOT-23	Public marking directory
BAT54SW	DIODES	—	Public marking directory
BAT54SWT	MCC	SOT-323	Public marking directory
BAT54W	NXP	SOT-323	Public marking directory
BAT54W	PHI	SC-70/SOT323	Public marking directory
HSMP-3864	AGILENT	SOT-23	Public marking directory
HSMP-386F	AGILENT	SOT-323	Public marking directory
KST1623-L4	FSC ^*	SOT-23	Public marking directory
MMBC1623L4	MOT	SOT-23	Public marking directory
NL17SZ32DF	ON ^*	SOT-353	Public marking directory
R1121N241A	RICOH ^*	SOT-23-5	Public marking directory
R3111N342C	RICOH ^*	SOT-23	Public marking directory
R3111Q141A	RICOH ^*	SC-82AB	Public marking directory
R3116Q111A	RICOH ^*	SC-82AB	Public marking directory
RN1105FS	TOS	—	Public marking directory
RN5RG44AA	RICOH ^*	SOT-23-5	Public marking directory
RN5RY341A	RICOH ^*	SOT-23-5	Public marking directory
TC7SL32F	TOS	SC-59	Public marking directory
TC7SL32FU	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 “L”

LT7 LTDPN L1 L2 L3 L5 L6 L7 L8 L9

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.