1N4477US/TR

Single Zener Diodes Overview

The Microchip Technology 1N4477US/TR is a surface mount Zener voltage regulator with a nominal breakdown voltage of 33 V. It operates within a junction temperature range of -65 °C to +175 °C and dissipates up to 1.5 W at 25 °C ambient conditions. The device features a maximum dynamic impedance of 800 Ohms at the test current of 7.5 mA, with a maximum reverse leakage current of 0.05 µA at 26.4 V. It utilizes a voidless hermetically sealed glass MELF package.

Single Zener Diodes Feature Summary

• Hermetically sealed voidless glass construction using internal metallurgical bonds for robust reliability.
• Military qualification available per MIL-PRF-19500/406 across JAN, JANTX, JANTXV, and JANS levels.
• Inherently radiation hard and non-sensitive to electrostatic discharge.
• Surface mount equivalent of popular JEDEC registered axial series.

Single Zener Diodes Applications

• High-reliability applications where failure cannot be tolerated.
• Voltage regulation over broad operating current and temperature ranges.
• Radiation-hardened circuit designs.

Single Zener Diodes Procurement Notes

Verify the specific reliability level suffix (JAN, JANTX, JANTXV, or JANS) required for your application, as these denote different qualification standards under MIL-PRF-19500/406. Confirm RoHS compliance status if applicable, noting that compliant versions are commercial grade only. Ensure the ordering part number matches the exact tolerance and package requirements specified in the design documentation.

Single Zener Diodes Selection Notes

Select this component for high-reliability surface mount designs requiring a 33 V reference. The 1.5 W power rating supports steady-state operation at elevated temperatures when derated appropriately. Consider the 800 Ohm dynamic impedance for noise sensitivity requirements. Verify thermal management needs against the junction-to-end cap thermal resistance of 20 °C/W.

Single Zener Diodes Part Context

This device belongs to the 1N4460US through 1N4496US series of 1.5 Watt Zener diodes. These components share a common A (D-5A) MELF package and voidless glass construction technology. The series covers a wide voltage range from 3.3 V to 200 V, offering standardized tolerances of 5%, 2%, and 1%.

Single Zener Diodes Replacement Considerations

Direct replacements must match the 33 V Zener voltage, 1.5 W power dissipation, and D-5A MELF package dimensions. Verify that substitute parts meet the same MIL-PRF-19500/406 military qualification levels if radiation hardness or extreme temperature operation is required.