PNDS / Marking codes / Y5

Identify an unknown SMD part: marking code “Y5”

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.

22 candidates 12 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
BZT52C18	MCC	SOD-123	Public marking directory
BZV49-C16	PHI	SOT-89	Public marking directory
BZV49C16	ZETEX	SOT89	Public marking directory
BZX84-A16	PHI	SOT-23	Public marking directory
BZX84-B16	NXP	SOT-23	Public marking directory
BZX84-C16	PHI	SOT23	Public marking directory
CMDZ5257B	CSC CENTRAL SEMIC.CORP. ^*	SOD-323	Public marking directory
MBR0520	MCC	SOD-123	Public marking directory
MM5Z16V	FSC	SOD-523	Public marking directory
MMSZ39	ON ^*	SOD-123	Public marking directory
R3111Q551C	RICOH ^*	SC-82AB	Public marking directory
R5325N005A	RICOH ^*	SOT-23-6	Public marking directory
BZT52-C16T	—	SOD-523	Public marking directory
BZX84-C16-V	—	SOT-23	Public marking directory
BZX88-C16	—	SOT-323	Public marking directory
ELM7645LBB	—	SOT-23 16vdc VD7 3d Elm	Public marking directory
FMY5	—	SOT-23-5	Public marking directory
MMSZ5260B	—	SOD-123	Public marking directory
R1163D351D	—	—	Public marking directory
R1210N552C	—	SOT-23-5	Public marking directory
XC6223H15BNR-G	—	SSOT-24	Public marking directory
ZD5241BSG	—	SOD-323-S	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 “Y”

Y1 Y3 YA YB YC YE YELLOW YF YK YP

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.