Active production — a 5.1 V reference that stays in the BOM
The 1N4733APE3/TR12: Rated for 1 W continuous power dissipation in a DO-204AL (DO-41) axial-lead package, it handles the thermal load of a shunt regulator or voltage clamp without needing a heatsink in free air.
±5% tolerance and 7 Ω impedance — what they mean for the circuit
The ±5% tolerance on the 5.1 V nominal means the actual zener voltage at the test current falls between 4.845 V and 5.355 V — tight enough for general-purpose regulation, but a calibration-grade reference would need the ±2% or ±1% suffix variants in the same 1N4733 family. Maximum zener impedance of 7 Ohms (Zzt) means the regulation voltage shifts by up to 7 mV per mA of load current change — acceptable for biasing a transistor stage or protecting a CMOS input, but a lower-impedance part is better for supplying a sensitive analog rail.
Temperature range and leakage — the reliability envelope
Operating from -65°C to 150°C, this diode covers the full military temperature band — it holds its zener voltage across the cold start of outdoor telecom gear and the hot soak of an engine bay. Reverse leakage is specified at 10 µA maximum with 1 V applied — low enough that it will not upset a high-impedance bias network or drain a battery in a standby circuit.
Tape & Reel for automated assembly
Supplied on Tape & Reel (TR), the 1N4733APE3/TR12 is ready for pick-and-place into through-hole axial insertion machines — the reel format suits volume production runs rather than prototype bench stock.