1N4557A

Single Zener Diodes Overview

The Microchip Technology 1N4557A is a single-terminal Zener diode with a nominal voltage of 3.9V and a tolerance of 10%. It utilizes a TO-3VAR flange mount package, featuring a metal body for robust thermal management. The device supports an operating temperature range from -65°C to +175°C. Key electrical characteristics include a maximum dynamic impedance of 0.16 Ω and a knee impedance of up to 400 Ω. The component is constructed from silicon and connects via two terminals.

Single Zener Diodes Feature Summary

• High-temperature stability suitable for extreme environments
• Robust metal flange mount construction for efficient heat dissipation
• Low dynamic impedance for precise voltage regulation

Single Zener Diodes Applications

• Precision voltage reference circuits in harsh conditions
• Industrial control systems requiring high thermal endurance
• Military-grade power supply regulation

Single Zener Diodes Procurement Notes

Verify the specific manufacturer source, as NXP is listed in available documentation. Confirm RoHS compliance status, which is marked as non-compliant in current records. Ensure the TO-3VAR package matches the mechanical design constraints of the target application before procurement.

Single Zener Diodes Selection Notes

Select this component when a stable 3.9V reference is required in high-temperature environments exceeding standard plastic package limits. The TO-3VAR package offers superior thermal performance compared to axial leads. Verify that the 10% voltage tolerance meets the circuit requirements, as tighter tolerances are not available in this specific part number.

Single Zener Diodes Part Context

This component belongs to the general-purpose Zener diode category, specifically designed for voltage regulation and reference applications. It is distinct from low-power glass-encapsulated variants by its high-power metal case construction. The series provides reliable performance in demanding industrial and aerospace sectors where thermal resistance is critical.

Single Zener Diodes Replacement Considerations

Cross-reference with other manufacturers offering TO-3VAR Zener diodes at 3.9V. Verify pinout compatibility and thermal resistance specifications. Note that military equivalents may require specific prefixes or suffixes depending on the original datasheet.