PNDS / Marking codes / S5

Identify an unknown SMD part: marking code “S5”

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.

23 candidates 12 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
1PS89SS05	PHI	SOT-490	Public marking directory
1PS89SS05	PHI	SC-89/SOT490	Public marking directory
BAT15-099	INFINEON	SOT143	Public marking directory
BBY52	INFINEON	SOT23	Public marking directory
BFQ31AR	FERRANTI	SOT-23	Public marking directory
R1121N351B	RICOH ^*	SOT-23-5	Public marking directory
R3116Q221C	RICOH ^*	SC-82AB	Public marking directory
SD103BW	DIODES	SOD-123	Public marking directory
SD103BWS	MCC	SOD-323	Public marking directory
SD103CW	MCC	SOD-123	Public marking directory
SD103CWS	MCC	SOD-323	Public marking directory
SST175	SILICONIX-VISHAY	SOT-23	Public marking directory
2SC3361-5	—	SOT-23	Public marking directory
BBQ31AR	—	SOT-23	Public marking directory
ELM7635HCB	—	SOT-23 16vdc VD7 3d Elm	Public marking directory
ELM9745CAB	—	SOT-89	Public marking directory
FS2J	—	DO-214AA	Public marking directory
R1131D151D	—	—	Public marking directory
R1163D151B	—	—	Public marking directory
R1225N252D	—	SOT-23-6W 33so	Public marking directory
R3130N46DA5	—	SOT-23	Public marking directory
RP104Q331D	—	SC-82AB	Public marking directory
XC6223C15BNR-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 “S”

S14 S2 S4 S6 SAM SAY SEI SIL SIX SK

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.