1N4746CP/TR8

Overview

The Microchip Technology 1N4746CP/TR8 is a silicon 1-watt Zener diode in the 1N4728AP through 1N4764AP series. It provides voltage regulation at a nominal 18V with a tight 2% tolerance, indicated by the 'C' suffix. The device operates within an ambient temperature range of -65°C to +150°C and features a plastic 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 13.7V, and a maximum regulator current of 250 mA.

Feature Summary

• Provides precise voltage regulation with a 2% tolerance on nominal Zener voltage
• Operates reliably across a wide temperature range from -65°C to +150°C
• Features flexible axial-lead mounting terminals for standard PCB integration
• Moisture classification is Level 1 per IPC/JEDEC J-STD-020B without requiring dry pack

Applications

• Voltage regulation over broad operating current and temperature ranges
• Reference voltage sources in electronic circuits
• Protection against voltage transients and spikes

Procurement Notes

Verify that the ordering suffix matches the required specifications. The 'P' indicates plastic construction, while 'TR' denotes tape and reel packaging. Confirm the 'C' suffix corresponds to the necessary 2% voltage tolerance. Ensure compatibility with RoHS requirements if applicable, as devices with the 'e3' suffix are compliant. Cross-reference datasheet electrical limits with circuit design parameters before procurement.

Selection Notes

Select this component when a stable 18V reference with high precision is required. The 2% tolerance makes it suitable for applications demanding tighter voltage control than standard 5% or 10% variants. Consider the 1W power dissipation rating and thermal resistance of 45°C/W junction-to-lead for heat management. The plastic DO-41 package offers lower thermal resistance compared to glass-body options.

Part Context

This part belongs to the Microsemi Scottsdale Division series of Silicon 1 Watt Zener Diodes. The series covers voltages from 3.3V to 100V. The 1N4746 designation specifically identifies the 18V variant within this extensive lineup. These devices are JEDEC registered and designed for general-purpose voltage regulation tasks in industrial and commercial electronics.

Replacement Considerations

Equivalent parts include other 18V Zener diodes with 1W power ratings and 2% tolerance. Surface mount equivalents such as SMAJ4746A or MLL4746A are available from the same manufacturer family. Verify pinout compatibility and thermal performance when substituting axial leads with surface mount packages.