1N4737APE3/TR8

Overview

The Microchip Technology 1N4737APE3/TR8 is a silicon 1.0-watt Zener diode in a plastic DO-41 axial lead package. It provides voltage regulation with a nominal Zener voltage of 7.5 V and a standard tolerance of ±5%. The device operates within a temperature range of -65°C to +150°C, featuring a maximum dynamic impedance of 4.0 Ohms at a test current of 34 mA. It includes RoHS compliance indicated by the e3 suffix and tape-and-reel packaging specified by the TR8 suffix.

Feature Summary

• Provides stable voltage regulation across a broad operating current and temperature range
• Features flexible axial-lead mounting terminals for through-hole applications
• Constructed with a void-free transfer molded thermosetting epoxy body meeting UL94V-0 standards
• Non-sensitive to electrostatic discharge (ESD) per MIL-STD-750 Method 1020

Applications

• Voltage regulation circuits requiring 7.5 V reference
• Power supply protection and clamping applications
• General purpose electronic equipment utilizing axial lead components

Procurement Notes

Verify the specific manufacturer origin, as the 1N4737A series was historically produced by Microsemi before its acquisition by Microchip Technology. Confirm that the e3 suffix denotes RoHS compliant annealed matte-Tin plating and that the TR8 suffix corresponds to the required tape and reel quantity. Ensure the plastic construction matches the design requirements instead of glass-body alternatives.

Selection Notes

Select this component when a 7.5 V Zener voltage with ±5% tolerance is required for through-hole assembly. The plastic DO-41 package offers lower thermal resistance compared to glass-body options. Consider the 1.0 W power dissipation rating and ensure adequate heat sinking or derating is applied if operating near maximum limits. Verify compatibility with existing PCB footprints designed for the DO-41 form factor.

Part Context

This part belongs to the 1N4728AP through 1N4764AP series of 1.0 Watt Zener Diodes. The series covers a wide voltage selection from 3.3 to 100 volts. The 'P' suffix indicates plastic encapsulation, while the 'e3' suffix confirms RoHS compliance. These devices are JEDEC registered and offer standard 5% tolerance for the 'A' suffix designation.

Replacement Considerations

Direct substitutes include other manufacturers' 1N4737A parts in the DO-41 package. For plastic variants specifically, check for equivalents with matching 7.5 V Zener voltage and 1 W power rating. Surface mount replacements like SMAJ4737A require circuit redesign due to package differences.