1N3340A

Single Zener Diodes Overview

The Microchip Technology 1N3340B is a high-power 50 W Zener diode within the 1N3305 through 1N3350B series. It provides voltage regulation with a nominal Zener voltage of 68 V at a test current of 180 mA. The device features a maximum dynamic impedance of 8.0 ohms and a maximum reverse current of 10 µA. It 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, with power derating of 0.5 W/°C above that threshold.

Single Zener Diodes Feature Summary

• Hermetically sealed welded construction with internal solder bond
• Standard polarity connects anode to case; reverse polarity available via suffix
• Inherently radiation hard per Microsemi MicroNote 050
• Non-sensitive to electrostatic discharge per MIL-STD-750 Method 1020

Single Zener Diodes Applications

• High power voltage regulation in military and aerospace systems
• Protection circuits requiring inherent radiation hardness
• Power supplies operating under extreme thermal conditions

Single Zener Diodes Procurement Notes

Verify the specific tolerance suffix required for your design, as the 'B' suffix indicates a +/- 5% Zener voltage tolerance. Confirm whether standard or reversed polarity (indicated by an 'R' suffix) is needed, as this affects mounting orientation. Ensure 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 when high power handling and radiation hardness are critical. The DO-5 package requires stud mounting, so verify mechanical compatibility with the heatsink interface. Consider the positive temperature coefficient above 5.6 V for thermal stability in high-voltage applications. Evaluate the maximum DC Zener current of 600 mA against the circuit's load requirements.

Single Zener Diodes Part Context

This part belongs to the 1N3305 through 1N3350B series of 50 W Zener diodes manufactured by Microsemi, now part of Microchip Technology. These devices are registered with JEDEC and offer a broad voltage selection from 3.9 V to 200 V. They are designed for rugged environments and are also available in JAN, JANTX, and JANTXV qualifications per MIL-PRF-19500/358.

Single Zener Diodes Replacement Considerations

Equivalent parts include other 50 W Zener diodes in the DO-5 package with matching voltage and current ratings. Verify that any substitute meets the same hermetic sealing and radiation hardness requirements if used in qualified applications.