1N3349A

Single Zener Diodes Overview

The Microchip Technology 1N3349B is a high-power 50 W Zener diode from the 1N3305 through 1N3350B series. It provides voltage regulation with a nominal Zener voltage of 180 V at a test current of 68 mA. The device features a maximum dynamic impedance of 90 ohms and a typical temperature coefficient of 0.095 %/°C. It 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.

Single Zener Diodes Feature Summary

• Hermetically sealed welded metal and glass construction for durability
• Internal solder bond design ensuring robust electrical connections
• Inherently radiation hard characteristics suitable for harsh environments
• Standard polarity configuration with anode connected to the case

Single Zener Diodes Applications

• High power voltage regulation circuits
• Radiation-hardened aerospace systems
• Military electronic equipment requiring MIL-PRF-19500/358 compliance
• Industrial power supplies operating under extreme thermal conditions

Single Zener Diodes Procurement Notes

Verify the specific suffix requirements when ordering. The 'B' suffix indicates a standard tolerance of +/- 5% on the Zener voltage. An 'R' suffix must be added to denote reversed polarity where the cathode connects to the case. Confirm that the application includes adequate heat sinking to maintain the case temperature below 75°C for full 50 W power dissipation capability.

Single Zener Diodes Selection Notes

Select this component for applications requiring high power handling in a stud-mount package. Ensure the system can accommodate the DO-5 (DO-203AB) mechanical footprint and the required mounting hardware. Consider the positive temperature coefficient above 180 V if thermal stability is critical. Verify that the reverse leakage current specifications meet the circuit's isolation requirements at the maximum operating temperature.

Single Zener Diodes Part Context

This part belongs to the Microsemi Scottsdale Division series of 50 Watt Zener diodes, which also includes the 1N4549B through 1N4556B variants. These devices are registered with JEDEC and are available in various military qualifications including JAN, JANTX, and JANTXV levels per MIL-S-19500/358. The series covers a broad voltage range from 3.9 V to 200 V.

Single Zener Diodes Replacement Considerations

Direct substitutes include other parts within the 1N3305 through 1N3350B series or the equivalent 1N4549B through 1N4556B series. For higher screening levels, consider parts prefixed with JAN, JANTX, or JANTXV. Surface mount equivalents are available upon consultation with the factory.