1N4777/TR

Overview

The 1N4777/TR is a temperature-compensated Zener diode manufactured by Microchip Technology. It features an 8.5 V nominal Zener voltage with a ±5% tolerance and operates within a power dissipation rating of 500 mW. The device utilizes a DO-204AH (DO-35) axial through-hole package. Key electrical specifications include a maximum reverse leakage current of 10 µA, a Zener impedance of 200 Ohms at a test current of 1 mA, and a voltage temperature coefficient of 0.001 %/°C. It supports an operating temperature range from -65°C to +175°C.

Feature Summary

• Temperature compensated design for stable voltage regulation across wide thermal ranges
• Single configuration in a standard axial leaded package for through-hole mounting
• High maximum operating temperature capability up to 175°C

Applications

• Precision voltage reference circuits requiring low temperature drift
• Overvoltage protection in high-temperature industrial environments
• Voltage regulator stages in aerospace or military-grade electronics

Procurement Notes

Verify the RoHS status carefully, as documentation indicates non-compliance. Confirm the specific suffix /TR denotes reel packaging when ordering. Ensure compatibility with DO-204AH footprint requirements. Check for any regional distribution restrictions or limited availability notices before finalizing procurement plans.

Selection Notes

Select this component when a stable 8.5 V reference is needed under varying thermal conditions. The low temperature coefficient makes it suitable for precision applications where standard Zeners would fail. Ensure the circuit can handle the 500 mW power dissipation and that the through-hole form factor fits the PCB layout constraints.

Part Context

This part belongs to the 1N47xx series of Zener diodes produced by Microchip Technology, formerly encompassing assets from Micrel and Actel. The 1N4777 variant specifically targets applications demanding temperature stability. The /TR suffix typically indicates tape and reel packaging for automated assembly processes.

Replacement Considerations

Direct substitutes must match the 8.5 V Zener voltage, 500 mW power rating, and DO-204AH package. Verify that alternative components offer comparable temperature coefficients and leakage current specifications to maintain circuit performance.