1N3319RB

Overview

The Microchip Technology 1N3319RB is a high-power 50 W Zener diode from the JEDEC registered 1N3305 through 1N3350B series. It provides voltage regulation with a nominal Zener voltage of 20 V at a test current of 630 mA and a maximum dynamic impedance of 2.4 ohms. The device features reversed polarity, indicated by the 'R' suffix, connecting the cathode to the case. It operates within a junction temperature range of -65°C to +175°C and utilizes a hermetically sealed DO-5 (DO-203AB) package with an 11/16 inch hexagonal stud.

Feature Summary

• Hermetically sealed welded metal and glass construction for durability
• Internal solder bond design ensuring robust mechanical integrity
• Reversed polarity configuration with cathode connected to the case
• Inherently radiation hard per Microsemi MicroNote 050

Applications

• High power voltage regulation in harsh environments
• Military and aerospace systems requiring radiation hardness
• Industrial equipment needing stable reference voltages under thermal stress

Procurement Notes

Verify the specific ordering suffix against official documentation to confirm polarity and tolerance requirements. Confirm that the required military qualification level (JAN, JANTX, or JANTXV) is explicitly stated if applicable, as standard parts may differ in screening levels. Ensure mounting hardware compatibility with the hexagonal stud specification before procurement.

Selection Notes

Select this component when a 20 V regulated output is required with high power dissipation capabilities up to 50 W. The reversed polarity design is critical for applications where the case must serve as the cathode terminal. Verify thermal management strategies to maintain case temperatures below 75°C for full power operation, considering the specified derating curve above this threshold.

Part Context

This part belongs to the Microsemi Scottsdale Division 1N3305 through 1N3350B series of 50 Watt Zener diodes. These devices are designed for broad voltage regulation ranges from 3.9 V to 200 V. The series includes variants with different voltage ratings and tolerances, sharing common mechanical and thermal characteristics suitable for demanding industrial and military applications.

Replacement Considerations

Equivalent parts include other 20 V 50 W Zener diodes in DO-5 packages with reversed polarity. Cross-reference with JAN or JANTX qualified versions like JANTX1N3319B if higher screening levels are required. Ensure any substitute matches the 2.4 ohm maximum dynamic impedance and thermal resistance specifications.