5.1 V regulation in a DO-214AC footprint
The SMAJ4733AE3/TR13 is a 5.1 V Zener diode in the standard DO-214AC (SMA) surface-mount package, rated for 2 W continuous power dissipation. This is the voltage a 5 V rail clamps to or a low-voltage reference holds — the ±5% tolerance means the actual Zener voltage sits between 4.845 V and 5.355 V across the operating range. With a maximum impedance of 7 Ohms (Zzt), the regulation sharpness at the nominal bias current is tight enough for most shunt-reference or clamping roles — the voltage shift per mA of load current stays under 7 mV.
Thermal and leakage profile for the BOM
Reverse leakage is specified at 10 µA maximum with only 1 V reverse bias — a useful guard against battery drain in always-on circuits where the Zener sits across a lightly loaded rail. Forward voltage is 1.2 V max at 200 mA, so the diode conducts with standard silicon drop when forward-biased — this matters if the part doubles as a low-side clamp in a bidirectional protection stage.
The TR13 suffix denotes Tape & Reel packaging, the standard format for high-volume pick-and-place assembly.