Identify an unknown SMD part: marking code “DX”

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 8 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
BCW68FR	SGS	SOT23R	Public marking directory
BCW68RF	SIEMENS	SOT-23	Public marking directory
BZX384-C75	NEXPERIA	SOD-323	Public marking directory
MAX6314US45D3-T	MAX *	SOT-143	Public marking directory
P6SMBJ90AC	LITTLE *	DO-214AA	Public marking directory
SM6T15A	ST	DO-214AA	Public marking directory
XC61119C37ANR-G	TOREX *	SSOT-24 26gh VD3 5c Tor	Public marking directory
XC6119C37ANR	TOREX *	SSOT-24	Public marking directory
AP131-38TW	—	—	Public marking directory
AP131-38W	—	SOT-23-5L	Public marking directory
AP131-38Y	—	SOT-89-5L	Public marking directory
AT1201-28X	—	SOT-23-5	Public marking directory
CD214B-T90CA	—	DO-214AA	Public marking directory
Cathode1	—	—	Public marking directory
HQ1A4A	—	SOT-89	Public marking directory
P4SMA220A	—	DO-214AC	Public marking directory
R5220D022B	—	—	Public marking directory
RT9809-46CV	—	SOT-23 16vdc VD7 3a Rct	Public marking directory
SiP809CJEUDDT	—	SOT-23	Public marking directory
TV06B900JB	—	DO-214AA	Public marking directory
XC6109C37AN	—	SSOT-24	Public marking directory
XC6127C49JNR	—	SSOT-24	Public marking directory
XC6127N50DNR	—	SSOT-24	Public marking directory

How we narrow this down

1. Package first — SOT-23 vs SOD-123 vs SC-59 eliminates most candidates immediately.
2. Pin count and body size — a 3-pin SOT-23 LDO cannot be a 6-pin dual transistor.
3. Marking style — laser-marked parts are usually newer production; ink marking often indicates older or second-source vendors.
4. Circuits around it — a part sitting on a rail with an inductor is a regulator, not a diode.
5. 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 “D”

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.