56 V Zener regulation at 500 mW
The 1N6018C is a 56 V Zener diode from Microchip Technology, rated for 500 mW continuous power dissipation in a DO-35 axial-lead package. The ±2% tolerance on the nominal Zener voltage means the regulation point stays between 54.88 V and 57.12 V at the specified test current — tight enough for a precision clamp or a reference rail in a low-power bias supply. Maximum impedance (Zzt) is 200 Ohms at the Zener test current, which sets the dynamic regulation slope. A 56 V rail drawing 5 mA sees roughly 1 V of additional drop across the diode due to this impedance — budget that into the worst-case output tolerance if the load current varies.
Thermal and leakage boundaries
Reverse leakage is specified at 100 nA maximum at 43 V reverse voltage — at 85°C ambient the leakage roughly doubles per 10°C rise, so a hot junction near 150°C may see leakage in the low microamp range, still negligible for most bias and clamping circuits. Forward voltage is 1.1 V maximum at 200 mA forward current — the diode conducts as a standard rectifier in the forward quadrant, useful if the same part serves double duty as a reverse-polarity clamp.