1N4777A/TR

Overview

The 1N4777A/TR is a temperature-compensated Zener reference diode manufactured by Microchip Technology. It features an 8.5 V nominal Zener voltage with a 5% tolerance and operates within a power dissipation of 0.5 W. The device utilizes a DO-35 axial glass package and is supplied in a tape-and-reel configuration for automated processing.

Feature Summary

• Temperature-compensated design for stable voltage reference applications
• Axial glass encapsulation for reliable through-hole mounting
• Tape-and-reel packaging format for high-volume assembly

Applications

• Precision voltage reference circuits
• Temperature-compensated regulator designs
• Calibration standards requiring stable DC levels

Procurement Notes

Verify the specific suffix '/TR' confirms the tape-and-reel packaging variant rather than bulk or single-unit formats. Confirm RoHS compliance status as historical data indicates potential non-compliance for certain revisions. Validate that the 8.5V specification aligns with the required circuit tolerance before finalizing procurement orders.

Selection Notes

Select this component when a stable, temperature-insensitive voltage reference is required in a standard axial package. The 0.5W power rating suits low-current reference applications. Ensure the PCB layout accommodates the DO-35 form factor and that the 8.5V output matches the system's reference requirements without additional scaling.

Part Context

This part belongs to the 1N47xx series of Zener diodes, specifically the temperature-compensated subset (1N4775–1N4784). Unlike standard Zeners, these devices utilize a combination of Zener and avalanche breakdown mechanisms to minimize voltage drift over temperature variations, making them suitable for precision analog references.

Replacement Considerations

Direct substitutes include other manufacturers' 1N4777A variants. Verify pinout compatibility and thermal characteristics when cross-referencing with generic equivalents.