1N4959US

Overview

The Microchip Technology 1N4959US is a surface mount Zener voltage regulator with a nominal breakdown voltage of 11 V. It features a maximum power dissipation of 5 W and operates within a junction temperature range of -65°C to +175°C. The device exhibits a test current of 125 mA, a dynamic impedance of 2.5 Ohms at IZT, and a maximum reverse leakage current of 10 µA. Voltage regulation accuracy is specified at 0.8 V, with a temperature coefficient of 0.07 %/°C.

Feature Summary

• Hermetically sealed voidless-glass construction with internal metallurgical bonds for high reliability
• Military qualified to MIL-PRF-19500/356 standards
• Inherently radiation hard and non-sensitive to electrostatic discharge

Applications

• High-reliability aerospace systems
• Defense electronics requiring failure-intolerant components
• Harsh environment circuit protection

Procurement Notes

Verify the specific manufacturer origin, as historical production involved Microsemi which was acquired by Microchip Technology. Confirm compliance with RoHS directives if required, noting that military variants may have different environmental specifications. Ensure the ordering suffix matches the desired tolerance level, as standard parts use a 5% tolerance without additional letters.

Selection Notes

Select this component when a robust, hermetically sealed surface mount solution is required for critical voltage regulation. The D-5B package offers a compact footprint suitable for space-constrained designs. Consider the thermal resistance characteristics and derating requirements above 140°C to ensure safe operation under continuous load conditions.

Part Context

This part belongs to the industry-recognized 1N4954US through 1N4996US series of 5 Watt Zener regulators. These devices are designed for applications where standard commercial components lack sufficient durability or longevity. The series provides extensive voltage selections from 3.3 to 390 volts in a standardized surface mount form factor.

Replacement Considerations

JAN1N4959US

FAQ

What is the maximum surge current rating?

The maximum nonrepetitive peak surge current is 19 A for an 8.3 ms square wave.

How is polarity indicated on the package?

Polarity is identified by a band marking on the cathode end of the device.