1N3318B

Overview

The Microchip Technology 1N3318B 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 19 V at a test current of 660 mA. The device features a maximum dynamic impedance of 2.2 Ohms and a maximum reverse current of 10 µA at 13.7 V. It operates within a junction temperature range of -65°C to +175°C, utilizing a DO-5 (DO-203AB) package with an internal solder bond construction.

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

Applications

• High power voltage regulation circuits
• Military and aerospace electronic systems
• Industrial equipment requiring robust thermal performance

Procurement Notes

Verify the specific suffix requirements when ordering, as prefixes like JAN or JANTXV indicate different screening levels per MIL-PRF-19500/358. Confirm that the standard polarity connects the anode to the case; use the R suffix if reversed polarity is required. Ensure adequate heat sinking is available to support the 50 W dissipation rating at case temperatures below 75°C.

Selection Notes

Select this component for applications demanding high power handling in a ruggedized form factor. The DO-5 stud mount package facilitates efficient thermal transfer. Consider the +/- 5% tolerance indicated by the B suffix for precise regulation needs. Evaluate the thermal resistance of 2.0°C/W maximum to ensure proper heat sink selection for your operating environment.

Part Context

This part belongs to the 1N3305 through 1N3350B series of 50 Watt Zener diodes manufactured by Microchip Technology's Scottsdale Division. These devices are designed for broad voltage regulation ranges from 3.9 V to 200 V. The series includes variants with military qualifications such as JAN, JANTX, and JANTXV, offering enhanced screening and reliability for critical applications.

Replacement Considerations

Equivalent parts include other 50 W Zener diodes in the DO-5 package with similar voltage ratings. Verify compatibility regarding polarity (anode-to-case vs. cathode-to-case) and thermal mounting requirements. Military equivalents may require specific prefix suffixes to match screening levels.