Active production — 39 V Zener for reference and clamping
The 1N6014A is an active-production Zener diode from Microchip Technology, nominally rated at 39 V with a ±10% tolerance, meaning the actual breakdown voltage for any given unit falls between 35.1 V and 42.9 V — a spread to budget in the regulator or clamp design. Housed in the DO-204AH (DO-35) axial-lead package, it is a through-hole part suited for point-to-point wiring, breadboard prototyping, or PCB assembly where hand-insertion or wave-solder is the process.
500 mW power ceiling and 170 Ohm impedance
Maximum power dissipation is 500 mW — at the 39 V Zener voltage, the continuous current is limited to about 12.8 mA before the junction temperature exceeds the safe operating area. The 170 Ohm maximum Zener impedance (Zzt) means the regulation voltage shifts by up to 170 mV per mA of load current, so the part is best suited for low-current reference or bias applications rather than power regulation. Reverse leakage is specified at 100 nA maximum when biased at 25 V, which is well below the Zener knee — useful in high-impedance divider networks where leakage current would otherwise shift the bias point.
The base product number is 1N6014; the 'A' suffix denotes a tighter tolerance variant (±10% vs the standard ±20% for the non-A version). No official pin-compatible second-source is listed, but the DO-35 package is a JEDEC standard footprint shared across many manufacturers' 500 mW Zener families.