1N4749A

Overview

The onsemi 1N4749A is a single-channel general-purpose Zener diode housed in a DO-41 through-hole package. It features a nominal Zener voltage of 20 V with a tolerance of ±5%. The device supports a maximum power dissipation of 1 W and operates within a temperature range of -65°C to +200°C. Key electrical parameters include a test current of 12.5 mA, a maximum Zener impedance of 22 Ω, and a maximum reverse leakage current of 5 μA.

Feature Summary

• Provides stable voltage regulation for low-voltage applications
• Utilizes glass passivation for environmental protection
• Features axial leads for reliable through-hole mounting

Applications

• Low voltage stabilizers
• Voltage reference circuits
• Overvoltage protection

Procurement Notes

Verify the specific manufacturer source, as the 1N4749A part number is produced by multiple vendors including onsemi, NXP, and others. Confirm compliance requirements such as RoHS status, as availability varies by supplier. Ensure the selected component matches the required DO-41 package dimensions and lead specifications for your assembly process.

Selection Notes

Select this component when a precise 20 V reference is needed in a standard axial package. Consider the 12.5 mA test current requirement for biasing circuit design. Evaluate thermal management needs given the 1 W power rating and high operating temperature limit. Compare alternative manufacturers if specific supply chain or certification constraints exist.

Part Context

This component belongs to the widely used 1N47 series of silicon Zener diodes. These devices are standardized for general voltage regulation tasks. The DO-41 package provides a robust mechanical solution for industrial and commercial electronics requiring through-hole integration.

Replacement Considerations

Compatible substitutes include other 1N4749A variants from different manufacturers like NXP or Vishay, provided they meet the same 20 V, 1 W, and DO-41 specifications.