1N4746A

Overview

The 1N4746A is a single silicon Zener diode designed for voltage regulation applications. It features a nominal Zener voltage of 18 V with a tolerance of ±5%. The device supports a maximum power dissipation of 1 W and operates within a temperature range from -65 °C to +200 °C. Key electrical parameters include a maximum reverse leakage current of 5 µA, a Zener impedance of 20 Ω at a test current of 14 mA. It is housed in the DO-41 axial leaded package.

Feature Summary

• Provides stable voltage regulation using a single unidirectional Zener junction.
• Capable of operating at elevated temperatures up to 200 °C.
• Constructed with glass encapsulation for environmental protection.

Applications

• General purpose voltage reference circuits
• Overvoltage protection stages
• Biasing networks in analog electronics

Procurement Notes

Verify the specific manufacturer suffix or packaging variant when ordering, as the base part number is utilized by multiple semiconductor producers including SMC Diode Solutions, onsemi, and Vishay. Confirm that the required package style (DO-41) and compliance standards match the target application requirements before finalizing procurement.

Selection Notes

Select this component for designs requiring an 18 V reference point with moderate power handling capabilities. Ensure the circuit design limits the current to maintain power dissipation below 1 W. Consider the 20 Ω dynamic impedance when high precision is required, as it affects regulation accuracy under varying load conditions.

Part Context

This component belongs to the standard 1N47xx series of Zener diodes, which are widely used for low-cost voltage regulation. The 1N4746A specifically targets the 18 V segment of this family. It serves as a fundamental discrete semiconductor device for maintaining constant potential differences in electronic systems.

Replacement Considerations

Cross-reference with other manufacturers' 1N4746A parts such as those from onsemi or Vishay. Verify pinout compatibility and thermal characteristics when substituting, as packaging dimensions may vary slightly between suppliers despite identical electrical ratings.