1N4549A

Single Zener Diodes Overview

The Microchip Technology 1N4549A is a high-power 50 W Zener diode from the 1N4549B-1N4556B series, designed for voltage regulation across a broad range. It features a nominal Zener voltage of 3.9 V with a test current of 3,200 mA and a maximum dynamic impedance of 0.16 Ohms at IZT. The device operates within a junction temperature range of -65°C to +175°C and dissipates up to 50 watts at a case temperature below 75°C. It utilizes a DO-5 (DO-203AB) package with an internal solder bond construction.

Single Zener Diodes Feature Summary

• Hermetically sealed welded metal and glass construction
• Internal solder bond construction for reliability
• Inherently radiation hard design
• Non-sensitive to electrostatic discharge

Single Zener Diodes Applications

• Voltage regulation in power supplies
• High power circuit protection
• Radiation-hardened electronic systems

Single Zener Diodes Procurement Notes

Verify the specific tolerance suffix required for your application, as the 'A' designation indicates a +/- 10% Zener voltage tolerance compared to the standard 'B' suffix. Confirm polarity requirements, noting that standard units have the anode connected to the case, while reverse polarity requires an 'R' suffix. Ensure adequate heat sinking is available to support the 50 W dissipation rating.

Single Zener Diodes Selection Notes

Select this component when high power handling and ruggedness are critical. The 1N4549A provides a low 3.9 V reference point within its series. Consider the thermal resistance of 2.0°C/W maximum when designing the mounting interface. Verify compatibility with MIL-PRF-19500/358 screening levels if military qualification is needed.

Single Zener Diodes Part Context

This part belongs to the 1N4549B through 1N4556B series of 50 Watt Zener diodes manufactured by Microsemi's Scottsdale Division. These devices are JEDEC registered and offer a wide selection of voltages from 3.9 V to 200 V. They are engineered for applications requiring robust voltage regulation under high power conditions.

Single Zener Diodes Replacement Considerations

Equivalent parts include the 1N3305 series, which shares identical electrical characteristics and physical dimensions. When substituting, ensure the replacement matches the required voltage tolerance suffix and polarity configuration.