1N4954

Overview

The Microchip Technology 1N4954 is a 6.8 V Zener Voltage Regulator with a 5 W power dissipation rating, qualified to MIL-PRF-19500/356. It features a hermetically sealed voidless-glass package with axial leads. Electrical characteristics at 25°C include a nominal voltage of 6.8 V at a test current of 175 mA, a maximum dynamic impedance of 1.0 Ohm at IZT and 1.5 Ohms at IZK=1mA, and a maximum reverse leakage current of 150 µA at 5.2 V. The device operates within a temperature range of -65°C to +175°C.

Feature Summary

• Military qualified to MIL-PRF-19500/356 for high-reliability applications
• Hermetically sealed voidless-glass construction with internal metallurgical bonds
• Triple-layer passivation and robust physical design
• Inherently radiation hard

Applications

• High-reliability voltage regulation circuits
• Military and aerospace electronic systems
• Harsh environment power supplies

Procurement Notes

Verify the specific ordering suffix (e.g., JAN, JANTXV) against the required military qualification level and tolerance class. Confirm that the component meets the exact MIL-PRF-19500/356 specification requirements for your application. Ensure proper handling procedures are followed due to the hermetic glass package and metallurgical bond construction.

Selection Notes

Select this component when a 6.8 V reference or regulator is needed in a 5 W through-hole package. Consider the 1.0 Ohm dynamic impedance at 175 mA for stability requirements. Verify thermal derating curves if operating above 65°C lead temperature. Check for surface-mount equivalents like the 1N4954US if board space is constrained.

Part Context

Part of the industry-recognized 1N4954 thru 1N4996 series of 5 Watt Zener Voltage Regulators. These devices are available in standard 5% tolerances and tighter tolerances identified by suffix letters. Surface mount versions exist in a square end-cap MELF configuration with a 'US' suffix.

Replacement Considerations

Direct replacements must match the 6.8 V Zener voltage, 5 W power rating, and MIL-PRF-19500/356 qualification. Equivalent parts from other manufacturers must provide identical electrical characteristics and hermetic sealing capabilities.

FAQ

What is the maximum continuous current for the 1N4954?

The maximum continuous current (IZM) is 700 mA.

How is polarity indicated on the 1N4954?

Polarity is indicated by a band on the body, which marks the cathode.