1N4774

Overview

The Microchip Technology 1N4774 is a temperature-compensated Zener reference diode with a nominal voltage of 9.1 V and a power dissipation rating of 500 mW. It utilizes a DO-204AH (DO-35) axial through-hole package. The device features a maximum voltage tolerance of ±5% and operates within a junction temperature range of -55°C to +175°C. Key electrical characteristics include a test current of 1 mA, a maximum impedance of 200 ohms at the test current, and a maximum temperature coefficient of 0.0005%/°C.

Feature Summary

• Temperature-compensated design for stable reference voltage performance across varying thermal conditions
• High stability with low temperature coefficient ensuring precise voltage regulation
• Robust glass encapsulation in an axial leaded package suitable for high-reliability applications

Applications

• Precision voltage reference circuits requiring thermal stability
• Regulated power supply designs utilizing Zener references
• Test and measurement equipment calibration standards

Procurement Notes

Verify the specific suffix (e.g., A, HR) against the required specifications, as these may indicate variations in plating or compliance status such as RoHS. Confirm the manufacturer source, as this part number is produced by multiple vendors including Microchip, STMicroelectronics, and others. Ensure the datasheet matches the exact electrical tolerances and package dimensions required for your PCB layout and thermal management strategy.

Selection Notes

Select this component when a stable 9.1 V reference is needed with minimal drift over temperature. The 500 mW power rating allows for higher current operation compared to lower-power variants. Consider the axial DO-35 package constraints for board space. Verify that the ±5% initial tolerance meets the system accuracy requirements without excessive trimming.

Part Context

This component belongs to the standard 1N47xx series of temperature-compensated Zener diodes. These devices are widely used in industrial and commercial electronics where reliable voltage referencing is critical. The 1N4774 specifically targets the 9.1 V segment, offering a balance between breakdown voltage and temperature stability characteristics common to compensated Zener structures.

Replacement Considerations

Direct substitutes include other manufacturers' 1N4774 parts which share identical electrical specifications. Cross-reference with 1N4774A if tighter tolerance or specific plating options are required. Ensure pinout compatibility with the DO-35 package form factor.