Microchip Technology lists the 1N6017B as Obsolete.
51 V regulation at 500 mW
The 1N6017B is a 51 V zener diode in a DO-35 axial-lead package. Rated at 500 mW maximum power dissipation, it provides voltage regulation or clamping in low-power circuits where the 51 V rail needs a stable reference. The ±5% tolerance means the actual zener voltage sits between 48.45 V and 53.55 V at the specified test current — tight enough for most bias and protection roles in analog supplies.
Leakage and impedance — what they mean for the circuit
Reverse leakage is 100 nA maximum at 39 V reverse voltage — a low enough draw that it won't load a high-impedance bias divider. Maximum zener impedance (Zzt) is 180 Ohms, which sets the dynamic resistance in the breakdown region; a higher Zzt means the regulation voltage shifts more with current, so the diode should be biased with a stable current source or a resistor sized to keep the operating point away from the knee.
Temperature range and forward drop
Operating junction temperature spans -65°C to +175°C — a military-grade temperature range that suits avionics, downhole, or satellite applications where the ambient swings wide. Forward voltage is 1.1 V maximum at 200 mA forward current, typical for a silicon junction diode of this class.