1N4746 G

Overview

The Microsemi Corporation 1N4746 G is a silicon unidirectional Zener voltage regulator diode designed for through-hole mounting. It features a DO-35-2 glass axial leaded package and provides an 18 V nominal Zener voltage with a 1 W power dissipation rating at ambient temperature. The device maintains a tight voltage tolerance of ±5% and operates within a wide junction temperature range from -65°C to +200°C. Key electrical characteristics include a maximum reverse leakage current of 5 µA and a dynamic impedance of 20 Ohms, ensuring stable regulation performance in various electronic circuits.

Feature Summary

• Provides precise voltage regulation using a silicon Zener junction with high thermal stability.
• Utilizes hermetically sealed glass encapsulation to protect against environmental degradation.
• Supports robust operation across extreme industrial temperature ranges up to 200°C.

Applications

• Voltage reference sources in precision measurement instrumentation
• Overvoltage protection circuits for sensitive semiconductor components
• Clamping applications in signal processing pathways

Procurement Notes

Verify the specific manufacturer designation when sourcing, as the 1N4746 series is produced by multiple vendors including Microchip Technology and onsemi. Confirm that the 'G' suffix corresponds to the intended glass axial package variant. Ensure compliance with project-specific material restrictions, noting that some variants may not meet RoHS standards. Cross-reference datasheets to validate exact electrical tolerances and thermal ratings before finalizing procurement.

Selection Notes

Select this component for designs requiring reliable through-hole voltage regulation with established industry-standard pinouts. The 1W power rating supports moderate current handling without excessive heat sinking. Consider the ±5% tolerance for general-purpose regulation tasks where tighter precision is unnecessary. Evaluate the operating temperature limits to ensure suitability for harsh environments exceeding standard commercial ranges.

Part Context

The 1N4746 belongs to a widely recognized family of 1 Watt Zener diodes standardized under JEDEC outlines. While originally defined by ON Semiconductor, the part number is now manufactured by several major semiconductor companies. This specific variant represents the classic axial glass package form factor, serving as a fundamental discrete component for basic power supply regulation and circuit protection functions.

Replacement Considerations

Direct functional equivalents include the 1N4746A from manufacturers such as Taiwan Semiconductor or onsemi. Verify package compatibility, as the Microsemi version may utilize the DO-35-2 outline while others use DO-41. Ensure replacement parts match the 18V nominal voltage and 1W power dissipation requirements.