1N3321B

Overview

The Microchip Technology 1N3321B 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 24 V at a test current of 520 mA. The device features a maximum dynamic impedance of 2.6 Ohms and a maximum reverse leakage current of 10 µA at 18.2 V. It operates within a junction and storage temperature range of -65°C to +175°C, dissipating up to 50 watts when mounted on a heat sink with a case temperature below 75°C.

Feature Summary

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

Applications

• Voltage regulation in power supplies requiring broad operating ranges
• Protection circuits utilizing inherent radiation hardness
• High-power dissipation applications with adequate mounting and heat sinking

Procurement Notes

Verify that the specific part number matches the required tolerance suffix, as the 'B' designation 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. Ensure the procurement documentation references the correct thermal management requirements for maintaining the case temperature below 75°C during operation.

Selection Notes

Select this component when a robust, hermetically sealed Zener diode is needed for high-power applications up to 50 W. The DO-5 package allows for stud mounting, which is essential for effective heat dissipation. Consider the specific Zener voltage and tolerance requirements, as the 'B' suffix ensures tighter voltage accuracy compared to other suffixes. Verify compatibility with the intended operating temperature range and radiation environment if applicable.

Part Context

The 1N3321B belongs to the Microsemi Scottsdale Division's line of 50 Watt Zener Diodes, covering the 1N3305 through 1N3350B series. This family offers a wide selection of voltages ranging from 3.9 V to 200 V. These devices are designed for high reliability and are available in various military qualifications, including JAN, JANTX, and JANTXV, by adding specific prefixes to the part number.

Replacement Considerations

Public confirmed substitute part numbers include 1N3321A and 1N3321RA.