Obsolete — sourcing through the surplus channel
Microchip Technology lists the 1N6008B as Obsolete.
22 V nominal, 500 mW — the key parametric fit
The 1N6008B is a 22 V zener diode with a ±5% tolerance band. Maximum power dissipation is 500 mW, which sets the current limit for the zener regulation or clamping function — at 22 V, the maximum continuous current is roughly 22.7 mA before the junction exceeds the thermal budget in free air. Reverse leakage is specified at 100 nA maximum at 17 V reverse voltage, which is 5 V below the nominal zener knee — this tells you the diode is fully off below the regulation point, important for low-power bias circuits where leakage current would otherwise drift the operating point. Maximum zener impedance (Zzt) is 55 Ohms — this is the dynamic resistance at the test current. A higher impedance means the regulation voltage shifts more with current variation; for a 1 mA change in zener current, the voltage shifts by roughly 55 mV.
DO-35 axial package — board-fit and temperature range
The glass body provides hermetic sealing — no moisture sensitivity level concern, and the construction handles the full -65°C to 175°C operating temperature range, which covers military and industrial thermal profiles. Forward voltage is 1.1 V maximum at 200 mA forward current — this is the conduction drop when the diode is forward-biased, not the zener regulation mode. The 500 mW power rating applies to both forward and reverse conduction; derate above 25°C ambient per the standard thermal derating curve for the DO-35 package.