1N4959

Overview

The Microchip Technology 1N4959 is a military-qualified, voidless hermetically sealed glass Zener diode rated for 5 watts of power dissipation. It provides an 11 V nominal Zener voltage with a standard 5% tolerance. The device operates within a junction temperature range of -65°C to +175°C and features flexible axial leads. Electrical characteristics include a maximum reverse leakage current of 10 µA at 8.4 V, a dynamic impedance of 2.5 Ω at the test current of 125 mA, and a continuous regulator current of 430 mA.

Feature Summary

• Hermetically sealed construction using voidless hard glass with tungsten slugs
• Military qualification compliant with MIL-PRF-19500/356 standards
• Robust internal metallurgical bonds ensuring high reliability
• Inherently radiation hard and insensitive to electrostatic discharge

Applications

• High-reliability aerospace systems where failure is not tolerated
• Voltage regulation in extreme environmental conditions
• Critical defense electronics requiring radiation hardness

Procurement Notes

Verify that the component matches the specific Microchip Technology datasheet requirements for the 1N4959 series. Confirm the package type is the standard axial lead configuration and check for any suffixes indicating tighter voltage tolerances or specific military grades. Ensure the supplier provides traceability documentation consistent with military procurement standards.

Selection Notes

Select this component when a robust, high-power Zener regulator is required for harsh environments. The 5 W rating supports significant current handling compared to lower-power variants. Verify that the 11 V breakdown voltage aligns with circuit design needs and that the axial lead form factor fits the available board space.

Part Context

This part belongs to the industry-standard 1N4954 through 1N4996 series of 5 Watt Zener Voltage Regulators. These devices are widely recognized for their durability and are designed for applications demanding long-term stability. The series covers a broad voltage range from 3.3 V to 390 V, offering flexibility for various high-power regulation tasks.

Replacement Considerations

Equivalent parts must match the 5 W power rating, 11 V Zener voltage, and axial lead package. Verify compatibility with MIL-PRF-19500/356 specifications if military qualification is required.