7.5 V regulation at 1 W — the bench-fit read
The 1N4737APE3/TR12 is a 7.5 V zener diode rated for 1 W continuous power dissipation in the DO-204AL (DO-41) axial package. The ±5% tolerance means the actual zener voltage lands between 7.125 V and 7.875 V at the test current — tight enough for a reference rail in a linear regulator or a clamp in a low-voltage supply.
Dynamic impedance and leakage — the so-what
Maximum zener impedance (Zzt) is 4 Ohms at the nominal 7.5 V point. That low dynamic resistance means the diode holds its regulation voltage within a few tens of millivolts as the bias current varies — useful when the same zener is both a reference and a load-dump clamp. Reverse leakage is 10 µA at 5 V, which is below the bias current of most shunt regulators, so it won't pull the reference node down in a high-impedance divider. Forward voltage is 1.2 V max at 200 mA — the diode can handle brief forward surges, but the 1 W dissipation limit governs continuous forward current.