1N4985US/TR

Single Zener Diodes Overview

The Microchip Technology 1N4985US/TR is a surface mount Zener voltage regulator with a nominal breakdown voltage of 130 V. It operates at a test current of 10 mA and features a maximum dynamic impedance of 190 Ohms at the test point, rising to 1250 Ohms at a knee current of 1 mA. The device dissipates up to 5 Watts at an case temperature of 140°C, with a thermal resistance of 7°C/W from junction to end cap. It withstands a continuous current of 36.6 mA and a surge current of 0.8 A for 8.3 ms square waves. The unit utilizes a D-5B (E) package, weighs 539 mg, and functions within a temperature range of -65°C to +175°C.

Single Zener Diodes Feature Summary

• Hermetically sealed voidless glass construction with internal metallurgical bonds
• Military qualification per MIL-PRF-19500/356 for high-reliability applications
• Robust design inherently resistant to electrostatic discharge
• Radiation hard characteristics suitable for harsh environments

Single Zener Diodes Applications

• High-reliability military electronic systems
• Aerospace power supply regulation circuits
• Critical voltage reference protection stages
• Harsh environment industrial control equipment

Single Zener Diodes Procurement Notes

Verify that the specific part number matches the required military qualification level and suffix specifications. Confirm compliance with material declarations and environmental standards relevant to the procurement region. Ensure the supplier provides traceable documentation for the hermetic seal integrity and metallurgical bond quality. Validate that the component lot aligns with the manufacturer's current production standards.

Single Zener Diodes Selection Notes

Select this component when a 5 Watt surface mount Zener diode with strict military reliability requirements is necessary. The 130 V rating and 10 mA test current define the operating point for voltage regulation tasks. Consider the D-5B package dimensions for PCB layout constraints. Evaluate the thermal management capabilities based on the specified junction-to-end cap thermal resistance and derating curves above 140°C.

Single Zener Diodes Part Context

This device belongs to the 1N4954US through 1N4996US series of surface mount Zener regulators manufactured by Microchip Technology's Scottsdale Division. These components are designed as industry-standard replacements for axial-leaded equivalents, offering voidless-glass construction and triple-layer passivation. The series covers a wide voltage range from 3.3 to 390 volts with standard 5% tolerances.

Single Zener Diodes Replacement Considerations

Axial-leaded equivalents such as the 1N4985 without the US suffix may be used if board space permits. Other variants in the 1N4954US through 1N4996US series offer different voltage ratings but share identical packaging and thermal characteristics.