1N4990

Single Zener Diodes Overview

The Microchip Technology 1N4990 is a military-qualified, voidless hermetically sealed glass Zener voltage regulator with a nominal breakdown voltage of 220 V. It operates within a junction temperature range of -65°C to +175°C and dissipates up to 5 Watts at a lead temperature of 65°C. The device features a standard 5% voltage tolerance and utilizes Category I internal metallurgical bonds for structural integrity. Electrical characteristics include a maximum reverse leakage current of 2 µA at 200 V and a dynamic impedance of 550 Ohms at the test current of 5 mA.

Single Zener Diodes Feature Summary

• Hermetically sealed voidless-glass construction with tungsten slugs
• Military qualification per MIL-PRF-19500/356
• Inherently radiation hard design
• ESD nonsensitive per MIL-STD-750 Method 1020

Single Zener Diodes Applications

• High-reliability aerospace systems
• Defense electronics requiring failure-free operation
• Harsh environment power regulation circuits

Single Zener Diodes Procurement Notes

Verify that the specific ordering suffix matches the required voltage tolerance and package configuration. Confirm compliance with the latest revision of MIL-PRF-19500/356. Ensure thermal management aligns with the specified derating curves above 65°C lead temperature. Validate material traceability and lot history for mission-critical deployments.

Single Zener Diodes Selection Notes

Select this component when high-voltage regulation is required in extreme environments. The 5W rating supports substantial power dissipation compared to lower-power series. Verify that the 220V breakdown voltage fits the circuit requirements. Consider the axial-lead termination style for through-hole mounting constraints.

Single Zener Diodes Part Context

This part belongs to the 1N4954 through 1N4996 series of 5 Watt Zener diodes manufactured by Microsemi (now Microchip). The series covers a wide voltage range from 3.3V to 390V. These devices are distinguished by their robust glass encapsulation and military-grade reliability standards, differentiating them from commercial equivalents.

Single Zener Diodes Replacement Considerations

Equivalent parts must match the 220V nominal voltage, 5W power rating, and hermetic sealing. Verify that any substitute meets MIL-PRF-19500/356 specifications. Check for identical axial lead dimensions and polarity markings.