1N4745A

Overview

The Microchip Technology 1N4745A is a hermetically sealed glass Zener voltage regulator diode designed for through-hole mounting in the DO-41 axial package. It provides a nominal Zener voltage of 16 V with a tolerance of ±5%. The device supports a maximum steady-state power dissipation of 1 W and operates within an extended temperature range from -65°C to +175°C. Key electrical characteristics include a maximum dynamic impedance of 16 Ohms at the test current of 15.5 mA, a forward voltage of 1.2 V at 200 mA, and a reverse leakage current of 5 µA at 12.2 V.

Feature Summary

• Hermetically sealed glass construction for environmental protection
• Temperature compensated Zener reference design
• Double plug metallurgical bond construction

Applications

• Voltage regulation circuits
• Overvoltage protection systems
• Reference voltage generation

Procurement Notes

Verify the specific manufacturer suffix (e.g., e3, G) as these indicate variations in compliance or packaging. Confirm RoHS status and lead-free plating requirements against project specifications. Ensure the DO-41 axial package aligns with PCB footprint constraints. Validate that the 1W power rating meets thermal management needs under worst-case operating conditions.

Selection Notes

Select this component when a robust, high-reliability Zener diode is required for harsh environments due to its hermetic sealing. The wide operating temperature range makes it suitable for industrial applications. Compare the 16V breakdown voltage and 1W power dissipation against circuit load requirements. Consider the low leakage current for precision reference applications.

Part Context

The 1N4745A belongs to the standard 1N47xxA series of 1-watt Zener diodes manufactured by Microchip Technology. This series is widely recognized for its reliability and consistent performance in discrete semiconductor applications. The part is often referenced in legacy designs and modern industrial equipment requiring stable voltage regulation.

Replacement Considerations

Equivalent parts include Fairchild Semiconductor 1N4745A_T50A and PANJIT 1N4745A_AY_00001. Verify pinout compatibility and thermal derating curves before substitution.