68 V Zener, 500 mW — the DO-35 workhorse
The 1N6020A is a 68 V Zener diode rated for 500 mW continuous power dissipation in the DO-35 axial-lead package — a standard through-hole form factor for point-to-point wiring, breadboard prototyping, or PCB insertion where surface-mount reflow isn't practical. With ±10% tolerance on the nominal Zener voltage, the regulation window sits between 61.2 V and 74.8 V — tight enough for most reference and clamping circuits in industrial control supplies and telecom line cards.
Leakage, impedance, and the thermal envelope
Reverse leakage is specified at 100 nA maximum when biased at 43 V — well below the Zener knee, so the diode draws negligible current in standby or bias applications until the breakdown region is reached. Maximum Zener impedance (Zzt) is 280 Ohms at the test current — this sets the dynamic resistance the regulator sees; a higher load current will shift the output voltage by the product of the load step and Zzt. Forward voltage is 1.1 V maximum at 200 mA forward current — useful when the diode is pressed into service as a general-purpose rectifier or flyback clamp in low-current DC rails.
Active lifecycle — sourcing posture
The DO-35 axial package ships in bulk (loose tube or bag) — no tape-and-reel variant is listed, so automated pick-and-place lines will need a tube feeder or manual insertion.