Active production — 5.1 V zener with tight ±2% tolerance
The 1N4733CPE3/TR8 is an active-production zener diode from Microchip Technology, rated 5.1 V nominal with ±2% tolerance and 1 W maximum power dissipation. The tight tolerance window means this part holds the regulation point closer than a standard ±5% zener — useful when the downstream circuit cannot tolerate a 250 mV shift at the reference node. Maximum zener impedance is 7 Ohms, which keeps the voltage variation across the operating current range lower than a higher-impedance part. Reverse leakage is specified at 10 µA at 1 V reverse voltage — low enough that in a battery-powered shunt regulator the leakage current does not dominate the quiescent budget.
This qualifies the diode for avionics, downhole instrumentation, and engine-bay electronics where the ambient temperature exceeds the 85°C or 125°C ceiling of commercial-grade zeners. The DO-204AL (DO-41) axial-lead package is through-hole mounted, compatible with wave-solder or hand-solder assembly. Tape & Reel packaging is specified, though the axial-lead form factor typically requires a custom feeder or manual placement in automated lines.