1N4118 (DO35)

Single Zener Diodes Overview

The Microsemi 1N4118 is a 27V Zener diode rated at 0.5W, housed in a hermetically sealed glass DO-35 (DO-204AH) axial-lead package. It features an internal metallurgical bond and meets MIL-PRF-19500/435 standards for JAN, JANTX, JANTXV, and JANS reliability levels. The device operates within a junction temperature range of -65°C to +175°C, with a maximum thermal resistance of 300°C/W. Electrical characteristics include a test current of 250µA, a maximum dynamic impedance of 150Ω, and a noise density of 40μV/√Hz.

Single Zener Diodes Feature Summary

• Internal metallurgical bond construction for enhanced structural integrity
• Hermetically sealed glass DO-35 package ensuring environmental protection
• Low noise density suitable for sensitive analog applications
• Qualified to military reliability levels including JANS

Single Zener Diodes Applications

• High-reliability voltage regulation circuits
• Precision reference voltage generation
• Radiation-hardened electronic systems
• Temperature-compensated circuit designs

Single Zener Diodes Procurement Notes

Verify the specific qualification level required, such as JAN, JANTX, JANTXV, or JANS, as these prefixes denote distinct manufacturing and screening standards per MIL-PRF-19500/435. Confirm RoHS compliance status if applicable, noting that commercial versions may differ from military-grade specifications. Ensure the ordering suffix matches the desired tolerance and packaging configuration before finalizing procurement.

Single Zener Diodes Selection Notes

Select this component when a stable 27V reference is needed in harsh environments requiring hermetic sealing. The internal metallurgical bond provides superior mechanical stability compared to non-bonded types. Consider the low noise density for precision applications and verify that the 0.5W power dissipation rating aligns with the thermal design constraints of the target system.

Single Zener Diodes Part Context

This part belongs to the 1N4099 through 1N4135 series of 500mW glass Zener diodes. The series offers a wide voltage selection from 1.8V to 100V with various tolerance options. These devices are designed for high-reliability applications and are available in both axial-lead and surface-mount packages, maintaining consistent performance across the broader product family.

Single Zener Diodes Replacement Considerations

Direct replacements must match the 27V nominal voltage, 0.5W power rating, and DO-35 package dimensions. Verify that substitute components meet the same MIL-PRF-19500/435 qualification levels if military reliability is required. Check for equivalent noise density and dynamic impedance specifications to ensure circuit compatibility.

Single Zener Diodes FAQ

What is the maximum operating temperature for the 1N4118?

The maximum junction and storage temperature for the 1N4118 is +175°C.

Does the 1N4118 feature an internal metallurgical bond?

Yes, the 1N4118 is constructed with an internal metallurgical bond, which is indicated by the "-1" suffix in the part number.

What is the typical capacitance of the 1N4118?

The datasheet provides a graph showing typical capacitance versus Zener voltage but does not list a single fixed value; it varies based on the specific operating conditions and voltage.