The 1N6004A is a 15 V Zener diode from Microchip Technology, rated at 500 mW continuous power dissipation in the DO-35 axial-lead package. The ±10% tolerance on Vz means the actual breakdown voltage for any given unit lands between 13.5 V and 16.5 V — wide enough for a shunt regulator or voltage clamp, but too loose for a precision reference without trimming.
Impedance and leakage — the fine print
Maximum Zener impedance (Zzt) is 42 Ohms at the test current. This dynamic resistance sets the regulation slope: a 10 mA load swing shifts the output by roughly 420 mV, which is acceptable for a crude clamp but limits use in a low-impedance rail. Reverse leakage is specified at 100 nA max when the applied voltage is 9.1 V, well below the breakdown knee. Leakage roughly doubles every 10°C rise, so at 125°C ambient the leakage can approach 1.6 µA — still negligible for most bias networks but worth budgeting in a high-impedance divider. Forward voltage drop is 1.1 V max at 200 mA forward current — typical for a silicon junction in this die size. The 500 mW power limit translates to about 33 mA continuous Zener current at 15 V; pulse operation can exceed this if the average stays under the thermal limit.
Temperature range and package — where it survives
The DO-35 glass package (DO-204AH) is hermetic — no moisture ingress, no popcorn risk during wave solder. The axial leads suit through-hole boards with 0.025-inch diameter holes on 0.200-inch lead spacing.
Active lifecycle — sourcing posture
Microchip Technology lists the 1N6004A as Active — no discontinuation notice, no last-time-buy window.