1N4977US

Single Zener Diodes Overview

The Microchip Technology 1N4977US is a surface mount Zener voltage regulator with a nominal breakdown voltage of 62 V. It operates within a test current range of 20 mA and supports a maximum continuous current of 76 mA. The device dissipates up to 5 Watts at an end cap temperature of 140°C, derating linearly to zero at 175°C. It features a dynamic impedance of 42 Ohms at the test point and maintains a maximum reverse leakage current of 2 µA at 47.1 V. The unit utilizes a voidless hermetically sealed glass package with tungsten slugs.

Single Zener Diodes Feature Summary

• Hermetically sealed voidless-glass construction with internal metallurgical bonds for high reliability
• Qualified to MIL-PRF-19500/356 standards for military applications
• Inherently radiation hard and non-sensitive to electrostatic discharge

Single Zener Diodes Applications

• High-reliability circuits where failure cannot be tolerated
• Voltage regulation over broad operating current and temperature ranges
• Military and aerospace electronic systems

Single Zener Diodes Procurement Notes

Verify that the specific part number matches the required military qualification standard. Confirm the package type corresponds to the surface mount configuration. Ensure the supplier provides documentation confirming the voidless hermetic seal and metallurgical bond integrity. Check for any suffix variations that may indicate tighter voltage tolerances or different testing criteria.

Single Zener Diodes Selection Notes

Select this component when a robust surface mount solution is required for critical voltage reference applications. The device offers a wide operating temperature range suitable for extreme environments. Consider the thermal resistance characteristics when designing heat dissipation paths. Verify compatibility with existing board layouts due to the specific pad dimensions.

Single Zener Diodes Part Context

This component belongs to the 1N4954US through 1N4996US series of 5 Watt Zener Voltage Regulators. The series provides extensive voltage selections from 3.3 to 390 volts. It serves as the surface mount equivalent to the axial-leaded 1N4954 through 1N4996 variants. The manufacturer also produces related series such as 1N5968US and 1N6632US.

Single Zener Diodes Replacement Considerations

JAN1N4977US

Single Zener Diodes FAQ

What is the thermal resistance from junction to end cap?

The thermal resistance is 7°C/W.

How is polarity indicated on the package?

The cathode is indicated by a band on the device.