1N3345B

Single Zener Diodes Overview

The Microchip Technology 1N3345B is a high-power 50 W Zener diode from the JEDEC registered 1N3305 thru 1N3350B series. It provides voltage regulation with a nominal Zener voltage of 140 V at a test current of 90 mA. The device features a maximum dynamic impedance of 60 Ohms and a reverse leakage current of 10 µA at 140 V. It operates within a junction temperature range of -65°C to +175°C and utilizes a DO-5 (DO-203AB) hermetically sealed metal and glass package.

Single Zener Diodes Feature Summary

• Hermetically sealed welded construction with internal solder bond for reliability
• Inherently radiation hard design suitable for harsh environments
• Standard polarity configuration with anode connected to the case
• Low thermal resistance enabling operation up to 50 W with adequate heat sinking

Single Zener Diodes Applications

• High power voltage regulation circuits
• Radiation-hardened electronic systems
• Industrial equipment requiring robust protection

Single Zener Diodes Procurement Notes

Verify that the specific part number matches the required tolerance suffix, as the 'B' suffix indicates a +/- 5% Zener voltage tolerance. Confirm the polarity requirement, noting that standard units have the anode to the case, while reversed polarity requires an 'R' suffix in the ordering code. Ensure mounting hardware specifications align with the hexagonal stud requirements for proper thermal management.

Single Zener Diodes Selection Notes

Select this component when applications demand high power dissipation capabilities up to 50 watts and strict environmental sealing. The 140 V nominal rating fits specific high-voltage regulation needs within the broader 3.9 V to 200 V series range. Consider the DO-5 package dimensions and stud mounting requirements during mechanical design integration to ensure adequate thermal contact and physical stability.

Single Zener Diodes Part Context

This device belongs to the 1N3305 thru 1N3350B series of high-power Zener diodes manufactured by Microsemi's Scottsdale Division. The series offers a broad selection of voltages from 3.9 V to 200 V, all sharing similar mechanical and electrical characteristics including hermetic sealing and radiation hardness. These components are designed for demanding applications where reliability and power handling are critical.

Single Zener Diodes Replacement Considerations

Equivalent parts include other 1N3345B variants from different manufacturers adhering to the same JEDEC registration. Military qualified versions such as JAN, JANTX, or JANTXV prefixes may be used if higher screening levels are required, provided they meet the same electrical and mechanical specifications.

Single Zener Diodes FAQ

What is the polarity configuration of the 1N3345B?

The standard polarity for the 1N3345B has the anode connected to the case. If reversed polarity (cathode to case) is needed, an 'R' suffix must be added to the part number.

Is the 1N3345B radiation hard?

Yes, the device is inherently radiation hard as described in Microsemi MicroNote 050.