1N4972

Single Zener Diodes Overview

The Microchip Technology 1N4972 is a military-qualified, voidless hermetically sealed glass Zener diode designed for high-reliability applications. It features a nominal Zener voltage of 39 V with a standard tolerance of ±5%. The device operates at a test current (IZT) of 30 mA and dissipates up to 5 Watts. Key electrical parameters include a maximum reverse leakage current of 2 µA at 29.7 V, a maximum Zener impedance of 14 Ω at IZT, and a temperature coefficient of +0.095 %/°C. It supports an operating junction temperature range from -65°C to +175°C.

Single Zener Diodes Feature Summary

• Voidless hermetically sealed glass package with internal metallurgical bonds for robust construction
• Military qualification per MIL-PRF-19500/356 for critical reliability environments
• Inherently radiation hard as described in Microsemi MicroNote 050
• ESD nonsensitive per MIL-STD-750 Method 1020

Single Zener Diodes Applications

• High-reliability aerospace systems
• Defense electronics requiring failure-intolerant components
• Radiation-hardened circuit protection
• Precision voltage regulation in extreme temperature environments

Single Zener Diodes Procurement Notes

Verify the specific ordering suffix against the manufacturer's datasheet to confirm exact performance tolerances and material specifications. Military variants such as JAN, JANTX, or JANS require strict adherence to MIL-PRF-19500/356 standards. Ensure that the procurement documentation includes full traceability and compliance certificates required for defense and aerospace supply chains.

Single Zener Diodes Selection Notes

Select this component when a 39 V reference is required in harsh environments. The 5 W power rating allows for significant current handling compared to lower-power equivalents. Consider the positive temperature coefficient (+0.095 %/°C) for thermal stability analysis. Verify lead finish requirements, noting that previous inventory utilized solid silver leads while current specifications indicate tin/lead finishes.

Single Zener Diodes Part Context

This part belongs to the industry-standard 1N4954 through 1N4996 series of 5 Watt Zener Voltage Regulators. These devices are recognized for their wide availability and standardized axial-lead mounting terminals. The series covers a broad voltage range from 3.3 V to 390 V, providing engineers with consistent packaging and reliability characteristics across various voltage selection needs.

Single Zener Diodes Replacement Considerations

Direct replacements must match the 39 V nominal voltage, 5 W power dissipation, and hermetic sealing. Surface-mount equivalents are available in MELF configuration with the 'US' suffix (e.g., 1N4972US), though mechanical integration differs. Lower military grades like JAN may substitute for higher grades if cost is a factor, provided all environmental qualifications remain acceptable.