1N4964CUS/TR

Overview

The Microchip Technology 1N4964CUS/TR is a military-qualified, surface-mount Zener voltage regulator with a nominal breakdown voltage of 18 V and a tight tolerance of ±1%. It operates within a junction temperature range of -65°C to +175°C and dissipates up to 5 Watts. The device features a voidless hermetically sealed glass package with tungsten slugs and copper end caps. Electrical characteristics include a maximum reverse leakage current of 5 µA at 13.7 V, a dynamic impedance of 4.0 Ω at the test current of 65 mA, and a positive temperature coefficient of 0.085 %/°C.

Feature Summary

• Military-grade qualification compliant with MIL-PRF-19500/356 for high-reliability applications
• Voidless hermetically sealed glass construction with internal metallurgical bonds
• Inherently radiation hard and non-sensitive to electrostatic discharge
• Tight voltage tolerance available via specific ordering suffixes

Applications

• High-reliability aerospace and defense circuits
• Critical voltage reference regulation in harsh environments
• Power supply protection where failure cannot be tolerated

Procurement Notes

Verify that the 'C' suffix correctly denotes the ±1% voltage tolerance required for the design. Confirm the 'US' suffix matches the specified surface mount package dimensions. Ensure the procurement order specifies tape and reel packaging if automated assembly is intended. Cross-reference the manufacturer's latest datasheet for any updates to mechanical or electrical specifications before finalizing the bill of materials.

Selection Notes

Select this component when a precise 18 V reference is needed in a ruggedized surface-mount environment. The ±1% tolerance makes it suitable for precision regulation tasks compared to standard 5% variants. Consider the 5 W power dissipation capability and thermal resistance when designing heat management solutions. Verify compatibility with lead-free soldering processes if RoHS compliance is mandatory for the end application.

Part Context

This part belongs to the industry-recognized 1N4954US through 1N4996US series of 5 Watt Zener Voltage Regulators. These devices are designed for applications requiring robust performance under extreme conditions. The series offers a wide selection of voltage values from 3.3 V to 390 V, providing engineers with standardized options for various power regulation needs in demanding industrial and military sectors.

Replacement Considerations

Equivalent axial-leaded versions exist as 1N4964 without the US suffix. Other manufacturers may offer similar 5 W SMT Zener diodes, but direct replacements must match the hermetic seal requirement and military qualification standards to ensure reliability in critical systems.