1N4678UR-1/TR

Overview

The Microchip Technology 1N4678UR-1/TR is a surface mount Zener diode in the DO-213AA package. It provides a nominal Zener voltage of 1.8 V with a standard tolerance of ±5%. The device operates at a test current of 50 µA and supports a maximum DC Zener current of 240 mA. It features a power dissipation rating of 0.5 W, a maximum reverse leakage current of 7.5 µA, and a forward voltage of 1.5 V at 100 mA. The unit operates within a junction temperature range of -65°C to +175°C.

Feature Summary

• Hermetically sealed glass DO-213AA MELF style package
• Internal metallurgical bond for high reliability
• Non-sensitive to ESD per MIL-STD-750 method 1020
• Inherently radiation hard

Applications

• Voltage regulation over broad operating current and temperature ranges
• High-reliability applications requiring hermetic sealing
• Radiation-hardened circuit designs

Procurement Notes

Verify the specific suffix configuration against official documentation to confirm RoHS compliance status and metallurgical bonding options. Confirm that the TR suffix indicates tape and reel packaging per EIA-481-1-B standards. Ensure the selected variant matches the required voltage tolerance and screening level for the intended application environment.

Selection Notes

Select this component when a hermetically sealed surface mount Zener diode is required for high-reliability or radiation-hardened environments. The internal metallurgical bond offers superior stability compared to standard commercial packages. Consider the low test current of 50 µA for sensitive biasing requirements and verify thermal derating curves for high ambient temperature operation.

Part Context

This part belongs to the 1N4678UR-1 thru 1N4717UR-1 series of 0.5 watt glass surface mount Zener voltage regulators. The series covers voltages from 1.8 to 43 volts. These devices serve as the surface mount equivalent of the JEDEC registered 1N4678 thru 1N4717 axial-leaded series, maintaining similar electrical characteristics in a compact DO-213AA package.

Replacement Considerations

The 1N4678UR-1 serves as the surface mount equivalent to the 1N4678-1 axial leaded version. Verify pinout compatibility and thermal resistance differences when substituting between package types.