1N4749P/TR12

Overview

The Microchip Technology 1N4749P/TR12 is a silicon 1.0-watt Zener diode in the 1N4728AP through 1N4764AP series, housed in a plastic DO-41 (DO-204AL) axial-lead package. It provides voltage regulation with a nominal Zener voltage of 24 V and a standard tolerance of ±10%. The device operates within a temperature range of -65°C to +150°C and features a maximum dynamic impedance of 25 ohms at a test current of 10.5 mA. The TR12 suffix indicates tape and reel packaging compliant with EIA-296 standards.

Feature Summary

• Provides stable voltage regulation across a broad operating current and temperature range
• Features flexible axial-lead mounting terminals for standard through-hole applications
• Constructed with a void-free transfer molded thermosetting epoxy body meeting UL94V-0 flammability ratings
• Offers lower thermal resistance compared to glass-body options for equivalent JEDEC part numbers

Applications

• Voltage regulation circuits requiring 1-watt power dissipation
• General-purpose electronic equipment protection
• Power supply reference voltage generation

Procurement Notes

Verify that the ordering suffix matches the required packaging configuration, as the TR12 designation specifically indicates tape and reel supply. Confirm compliance requirements such as RoHS status if applicable, noting that specific environmental certifications may require an e3 suffix. Ensure the procurement documentation aligns with the manufacturer's specified moisture classification level and screening levels if military-grade performance is necessary.

Selection Notes

Select this component when a 24 V regulation point with 10% tolerance is required in a high-power 1-watt axial package. Consider the plastic construction for improved thermal characteristics over glass variants. Evaluate the maximum reverse current and dynamic impedance specifications against circuit sensitivity requirements. Verify that the operating temperature range meets the environmental conditions of the target application.

Part Context

This device belongs to the widely used 1N47xx series of silicon Zener diodes manufactured by Microchip Technology (formerly Microsemi). The series covers a voltage range from 3.3 V to 100 V, offering extensive selection for various regulation needs. The P suffix denotes plastic encapsulation, distinguishing it from the glass-bodied G suffix versions while maintaining compatibility with standard JEDEC mechanical outlines.

Replacement Considerations

Equivalent parts include other manufacturers' 1N4749A or 1N4749AP devices in the DO-41 package. For surface mount replacements, consider SMAJ4749A or MLL4749A equivalents. Verify that substitute components meet the same 1-watt power dissipation and 24 V Zener voltage specifications.