5.1 V shunt regulation — the parametric baseline
The 1N4733PE3/TR8 is a 5.1 V Zener diode from Microchip Technology's 1N4733 family, rated for 1 W continuous power dissipation in a through-hole DO-204AL (DO-41) axial package. With a ±10% tolerance, the nominal 5.1 V breakdown sits between 4.59 V and 5.61 V — a band that suits general-purpose rail clamping or low-accuracy shunt regulation where a tighter reference is not required.
Thermal and dynamic behaviour
Maximum Zener impedance (Zzt) is 7 Ohms at the test current — this is the dynamic resistance at the breakdown knee; a lower Zzt means better voltage regulation as the bias current varies, though for a 1 W part the regulation is adequate for load currents up to roughly 196 mA (the 1 W / 5.1 V derating limit). Reverse leakage is specified at 10 µA maximum when the applied voltage is 1 V — well below the breakdown threshold, confirming the diode blocks cleanly in the off-state for low-power battery circuits where standby current matters.
The DO-204AL (DO-41) axial-lead package is a through-hole industry standard — the 0.025-inch diameter leads suit 0.040-inch plated-through holes on single-sided or double-sided boards, and the body stands off the board naturally for convective cooling. Supplied on Tape & Reel (TR), the diode is ready for automated insertion equipment — the reel quantity supports volume builds without manual handling of loose parts.
Active lifecycle — sourcing posture
The design-in risk is low for new builds.