7.5 V regulation, 1 W dissipation, DO-41 axial
The 1N4737CPE3/TR8 is a 7.5 V Zener diode from Microchip Technology's 1N4737 series, rated for 1 W continuous power dissipation in the standard DO-204AL (DO-41) axial-lead package. The ±2% tolerance on the nominal voltage means the actual Zener voltage at the test current falls between 7.35 V and 7.65 V — tight enough for a basic shunt regulator or voltage reference in a low-precision rail. Maximum impedance (Zzt) is 4 Ohms at the Zener test current, so the regulation slope is shallow: a 10 mA change in current shifts the output voltage by about 40 mV. Reverse leakage is specified at 10 µA maximum with 5 V reverse bias, which is the 1N4737's standard guard-band for off-state current in a 5 V logic supply clamp.
The DO-204AL (DO-41) glass-passivated body is a through-hole axial package — it solders into a 0.040-inch diameter hole on a standard PCB or protoboard, and the lead bend radius should stay above 1.5 mm to avoid cracking the glass seal. The Tape & Reel (TR) suffix means these ship on a 13-inch reel with 5000 pieces per reel, which is the standard production quantity for axial-lead diodes.