The 2SD789ETZ is a small-signal NPN bipolar transistor from *, designed for general-purpose amplification and switching in through-hole assemblies. As a small-signal device, it handles low to moderate current and voltage in analog and digital circuits where a discrete transistor provides the gain or switching function — think pre-driver stages, signal conditioning, relay or LED drivers, and interface logic level translation.
This is typical for legacy through-hole transistors that were designed before the RoHS directive and have not been converted to a lead-free finish. If your BOM requires full RoHS compliance for the end product (e.g., CE marking, consumer electronics sold in the EU), this part will not pass incoming inspection. However, for military, aerospace, or industrial equipment that operates under a RoHS exemption (e.g., leaded solder in high-reliability assemblies), the non-compliant status is acceptable and often preferred for its proven long-term reliability and tin-whisker resistance.
Sourcing the 2SD789ETZ
For procurement, this means no last-time-buy urgency and no forced redesign to a substitute. The RoHS non-compliant status may limit stock at some distributors that only carry lead-free inventory, but the active lifecycle means production lots are still being run.