PNDS / Marking codes / ER

Identify an unknown SMD part: marking code “ER”

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.

24 candidates 9 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
2SC5097-R	TOS	SMQ	Public marking directory
BD4855FVE	ROHM ^*	VSOF-5	Public marking directory
BD4855G	ROHM ^*	SSOP-5	Public marking directory
P6SMBJ170AC	LITTLE ^*	DO-214AA	Public marking directory
R1112N151A	RICOH ^*	SOT-23-5	Public marking directory
R3112Q451C	RICOH ^*	SC-82AB	Public marking directory
SM6T30A	ST	DO-214AA	Public marking directory
XC61119C42ANR-G	TOREX ^*	SSOT-24 26gh VD3 5c Tor	Public marking directory
XC6119C42ANR	TOREX ^*	SSOT-24	Public marking directory
2SB789A-R	—	SOT-89	Public marking directory
2SC4807	—	SOT-89	Public marking directory
2SC5814-R	—	SC-59	Public marking directory
2SC5815-R	—	SC-70	Public marking directory
2SC5816-R	—	SC-75A	Public marking directory
2SC5817-R	—	—	Public marking directory
AT1201-27XR	—	SOT-23-5	Public marking directory
CD214B-T170CA	—	DO-214AA	Public marking directory
RT9167-40CB	—	SOT-23-5	Public marking directory
SiP809CMEUDT	—	SOT-23	Public marking directory
TV06B171JB	—	DO-214AA	Public marking directory
XC6109C42AN	—	SSOT-24	Public marking directory
XC6127C39KNR	—	SSOT-24	Public marking directory
XC6127N40ENR	—	SSOT-24	Public marking directory
Z1SMA-20	—	DO-214AC	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 “E”

EK EV E0 E1 E2 E3 E4 E5 E6 E8

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.