1N3319RA

Overview

The Microchip Technology 1N3319RA is a high-power 50 W Zener diode from the 1N3305-1N3350B series. It provides voltage regulation with a nominal Zener voltage of 20 V at a test current of 630 mA. The device features a maximum dynamic impedance of 2.4 Ω and a typical temperature coefficient of +0.075 %/°C. It operates within a junction and storage temperature range of -65°C to +175°C, dissipating up to 50 W at a case temperature below 75°C. The unit utilizes a 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
• Reverse polarity configuration with cathode connected to the case
• Inherently radiation hard capability suitable for harsh environments

Applications

• High power voltage regulation in aerospace systems
• Overvoltage protection in military-grade electronic circuits
• Power supply stabilization in industrial equipment requiring thermal resilience

Procurement Notes

Verify that the specific part number includes the 'R' suffix to confirm reversed polarity orientation where the cathode connects to the case. Ensure procurement specifications align with the required tolerance level, as the 'B' suffix denotes a +/- 5% Zener voltage tolerance. Confirm that the supplier sources units meeting the JEDEC registered standards or specified military qualifications if applicable to the system requirements.

Selection Notes

Select this component when applications demand high power dissipation capabilities up to 50 W combined with extreme temperature operation up to +175°C. The reverse polarity variant is essential for designs requiring the cathode terminal to be electrically common with the mounting chassis. Consider the low thermal resistance of 2.0 °C/W to ensure effective heat sinking strategies are implemented for reliable long-term performance under continuous load conditions.

Part Context

This device belongs to the Microsemi Scottsdale Division 1N3305 through 1N3350B series of 50 Watt Zener diodes. These components are designed for broad voltage regulation ranging from 3.9 V to 200 V. The series is available in standard, JAN, JANTX, and JANTXV qualifications per MIL-PRF-19500/358, catering to diverse reliability requirements across commercial and defense sectors.

Replacement Considerations

Equivalent parts within the 1N3305-1N3350B series may be considered if they match the 20 V rating and DO-5 package dimensions. Verify that any substitute maintains the same reverse polarity configuration and hermetic sealing characteristics to ensure compatibility with existing mounting hardware and electrical interface constraints.