Marking SMD, SMD Codes 31, 315, 317.

Datasheets BCR321U, STF203-15, ZXTP23015CFHTA.
SMD CodePackageDevice NameManufacturerDataDatasheet
31SC-74BCR321UInfineonLED DriverDownload datasheet
315SC70-6LSTF203-15SemtechUSB Upstream Port Filter and TVS For EMI Filtering and ESD ProtectionDownload datasheet
317SOT-23ZXTP23015CFHTAZetex15V, PNP Medium Power TransistorDownload datasheet