1N4477US

Single Zener Diodes Overview

The Microchip Technology 1N4477US 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 temperature. The device features a maximum dynamic impedance of 25 Ohms at a test current of 7.5 mA, with a maximum reverse leakage current of 0.05 µA at 26.4 V. It utilizes a hermetically sealed voidless glass MELF package.

Single Zener Diodes Feature Summary

• Hermetically sealed voidless glass construction with internal metallurgical bonds for high 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

Single Zener Diodes Applications

• High-reliability military and aerospace circuits where failure is not tolerated
• Voltage regulation over broad operating current and temperature ranges
• Radiation-hardened electronic systems

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 when a surface mount Zener diode with 1.5 W power dissipation and wide temperature capability is needed. The 1N4477US provides a 33 V reference point with low leakage characteristics. Consider the thermal resistance from junction to end cap when designing heat dissipation paths for continuous operation near maximum ratings.

Single Zener Diodes Part Context

This device belongs to the 1N4460US through 1N4496US series of industry-recognized Zener regulators. These components serve as surface mount equivalents to popular JEDEC registered axial-lead series, offering identical electrical performance in a compact D-5A MELF package suitable for automated assembly processes.

Single Zener Diodes Replacement Considerations

Direct parameter-equivalent replacements include the 1N4477D (DO-41 axial lead) and other variants within the 1N4460US–1N4496US series. Verify package compatibility and mounting constraints when substituting axial leads for surface mount devices.