1N4746APE3/TR8

Overview

The Microchip Technology 1N4746APE3/TR8 is a silicon 1.0-watt Zener diode in the 1N4728AP through 1N4764AP series, manufactured by the Microsemi Scottsdale Division. It provides voltage regulation with a nominal Zener voltage of 18 V and a standard tolerance of ±5%. The device features a plastic encapsulated DO-41 (DO-204AL) axial-lead package. Electrical characteristics include a maximum dynamic impedance of 20 Ohms at a test current of 14 mA, a maximum reverse current of 5 µA at 13.7 V, and a maximum regulator current of 250 mA. It operates within a temperature range of -65°C to +150°C.

Feature Summary

• Provides stable voltage regulation across a broad operating current and temperature range
• Features flexible axial-lead mounting terminals for through-hole installation
• Constructed with void-free transfer molded thermosetting epoxy body meeting UL94V-0 standards
• RoHS compliant devices available with an e3 suffix indicating annealed matte-Tin plating

Applications

• Voltage regulation circuits requiring 18 V reference
• Power supply protection and clamping applications
• General purpose electronic equipment utilizing axial-lead components

Procurement Notes

Verify that the ordering suffix TR8 corresponds to the tape and reel packaging option described in the datasheet as adding a TR suffix. Confirm the component originates from the Microsemi Scottsdale Division documentation. Ensure the specific batch meets the RoHS compliance requirements indicated by the e3 suffix. Cross-reference the JEDEC type number 1N4746A to validate the electrical parameters against the official specifications.

Selection Notes

Select this component when a 18 V Zener voltage with 5% tolerance is required for power dissipation up to 1.0 watt. The plastic construction offers lower thermal resistance compared to glass-body options. Consider the DO-41 package dimensions for board layout. Verify that the operating environment stays within the specified -65°C to +150°C temperature range for reliable performance.

Part Context

This part belongs to the popular 1N4728AP through 1N4764AP series of 1.0 watt Zener diodes. The series covers a voltage selection from 3.3 to 100 volts. These plastic encapsulated Zeners are moisture classified as Level 1 per IPC/JEDEC J-STD-020B, requiring no dry pack. The P suffix designates plastic construction, distinguishing it from glass-body variants.

Replacement Considerations

Consult the factory for surface mount equivalents such as SMAJ4746A or MLL4746A. Military screening levels are available by adding MQ, MX, MV, or MSP prefixes respectively.