What the 75 V Zener voltage means for your rail
The 1N6021A is a 75 V Zener diode from Microchip Technology in the standard DO-35 axial-lead package. The 75 V nominal breakdown sets the regulation point — a 75 V rail or a clamped node will sit within ±10% of that voltage across the rated current range, which is the tolerance band you design the downstream load around.
Power and temperature — the thermal budget
Rated for 500 mW maximum power dissipation in the DO-35 package. The wide operating temperature range of -65°C to 175°C covers military and industrial extremes — the junction temperature limit is the same 175°C, so derating is required above 25°C ambient if the full 500 mW is dissipated continuously. Reverse leakage is specified at 100 nA maximum when the applied reverse voltage is 47 V, well below the Zener knee. Forward voltage drop is 1.1 V maximum at 200 mA forward current — useful if the diode is also used as a general-purpose rectifier in the same BOM position.
No end-of-life notice or successor has been issued.