1N4549B

Single Zener Diodes Overview

The Microchip Technology 1N4549B is a high-power 50 W Zener diode with a nominal voltage of 3.9 V and a test current of 3,200 mA. It features a maximum dynamic impedance of 0.16 Ω at the test current and a typical temperature coefficient of -0.046 %/°C. The device operates within a junction and storage temperature range of -65°C to +175°C, dissipating up to 50 watts at a case temperature below 75°C. It utilizes a DO-5 (DO-203AB) hermetically sealed metal package with an anode-to-case standard polarity.

Single Zener Diodes Feature Summary

• Hermetically sealed welded construction with internal solder bond for reliability
• Inherently radiation hard design suitable for harsh environments
• Low thermal resistance enabling operation at full power with adequate heat sinking
• Non-sensitive to electrostatic discharge per MIL-STD-750 Method 1020

Single Zener Diodes Applications

• Voltage regulation in aerospace and defense systems
• High-power industrial equipment requiring robust voltage references
• Military applications utilizing JAN, JANTX, or JANTXV qualifications

Single Zener Diodes Procurement Notes

Verify the specific revision level and manufacturing origin when sourcing this component. Confirm that the supplier provides documentation regarding the hermetic seal integrity and adherence to the original JEDEC registration standards. Ensure the procurement channel supports traceability requirements for military-grade variants if applicable.

Single Zener Diodes Selection Notes

Select the 1N4549B for applications requiring precise low-voltage regulation at high currents. Consider the negative temperature coefficient when designing circuits sensitive to thermal drift. Ensure the mechanical mounting hardware accommodates the hexagonal stud and verify that the thermal interface maintains the case temperature below 75°C for full 50 W dissipation.

Single Zener Diodes Part Context

This component belongs to the 1N4549B through 1N4556B series of 50 Watt Zener diodes manufactured by Microsemi's Scottsdale Division. These devices are part of a broader family offering voltages from 3.9 V to 200 V. The series is characterized by its rugged DO-5 package and availability in various military screening levels.

Single Zener Diodes Replacement Considerations

Direct substitutes include other parts within the 1N4549B-1N4556B series or the parallel 1N3305-1N3350B series. For equivalent performance, ensure the replacement matches the 3.9 V nominal voltage, 50 W power rating, and DO-5 package dimensions.