PNDS / Marking codes / LD

Identify an unknown SMD part: marking code “LD”

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
2SA1736	MCC	SOT-89	Public marking directory
2SA812-M4	MCC	SOT-23	Public marking directory
2SC4357-D	TOS ^*	SOT-89	Public marking directory
BF543	INFINEON	SOT-23	Public marking directory
BU4944F	ROHM ^*	SOP-4	Public marking directory
BU4944FWE	ROHM ^*	VSOF-5	Public marking directory
BU4944G	ROHM ^*	SSOP-5	Public marking directory
P6SMBJ12	LITTLE ^*	DO-214AA	Public marking directory
R1114Q331A	RICOH ^*	SOT-143R	Public marking directory
SM6T6V8C	ST	DO-214AA	Public marking directory
2SC2462-D	—	SOT-23	Public marking directory
2SC5850-D	—	SOT-23	Public marking directory
AX6601-15R	—	SOT-23L 16cg VR1 3b Axl	Public marking directory
ELM7633HDB	—	SOT-23 16vdc VD7 3d Elm	Public marking directory
HD2A4M	—	SOT-89	Public marking directory
P6SMB18	—	DO-214AA	Public marking directory
PT7M6230CHC4	—	SC-70-4	Public marking directory
PT7M6230CHC4E	—	SC-70-4	Public marking directory
RF1	—	—	Public marking directory
RP130Q151D	—	SC-82AB	Public marking directory
RT9168-28CBR	—	SOT-23-5	Public marking directory
TV06B120K	—	DO-214AA	Public marking directory
XC6120C43N	—	SSOT-24	Public marking directory
XC6127N22JNR	—	SSOT-24	Public marking directory
XC6223F231NR-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 “L”

LT7 LTDPN L1 L2 L3 L4 L5 L6 L7 L8

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.