The RD43F is a Zener diode from the * series, designed for voltage regulation and clamping in DC circuits.
RoHS status — a compliance decision point
The RD43F is marked RoHS non-compliant. If your BOM is bound for a region where RoHS exemption or leaded solder is permitted (military, aerospace, some industrial or medical legacy builds), this part fits. For a standard commercial or consumer product requiring full RoHS compliance, you will need a lead-free Zener alternative — the RD43F is not that part.
Sourcing the RD43F
Because it is an active Zener diode with no announced end-of-life, it remains a viable line item for production BOMs that accept non-RoHS components.