1N4555A

Single Zener Diodes Overview

The Microchip Technology 1N4555A is a high-power 50 W Zener diode designed for voltage regulation within the 1N4549B through 1N4556B series. It provides a nominal Zener voltage of 6.8 V with a standard tolerance of ±5%. The device operates at a test current of 1,850 mA and features a maximum dynamic impedance of 0.16 Ohms. It utilizes a hermetically sealed DO-5 (DO-203AB) package with an 11/16 inch hexagonal stud for mounting. The component supports junction temperatures from -65°C to +175°C and includes internal solder bond construction.

Single Zener Diodes Feature Summary

• Hermetically sealed welded metal and glass construction
• Internal solder bond construction
• Standard polarity connects anode to case
• Inherently radiation hard

Single Zener Diodes Applications

• Voltage regulation in power supplies
• High power dissipation circuits requiring adequate heat sinking
• Military applications qualifying under MIL-PRF-19500/358

Single Zener Diodes Procurement Notes

Verify the specific suffix requirements for tolerance and polarity before ordering. The 'B' suffix indicates a ±5% voltage tolerance, while an 'R' suffix denotes reverse polarity where the cathode connects to the case. Confirm that the application environment meets the specified thermal resistance and power derating curves for reliable operation above 75°C case temperature.

Single Zener Diodes Selection Notes

Select this component when a 6.8 V reference with high current handling capability is required. Ensure the design accommodates the 1,850 mA test current and the physical dimensions of the DO-5 stud mount package. Verify that the system can manage the 50 W power dissipation through appropriate thermal management strategies as defined by the manufacturer's derating guidelines.

Single Zener Diodes Part Context

This part belongs to the 1N4549B through 1N4556B series of 50 Watt Zener diodes manufactured by Microsemi, now part of Microchip Technology. These devices are JEDEC registered and offer a broad range of voltages from 3.9 V to 200 V. The series is characterized by low thermal resistance and robust construction suitable for demanding industrial and military environments.

Single Zener Diodes Replacement Considerations

Equivalent parts include other 50 W Zener diodes in the DO-5 package with a 6.8 V rating and ±5% tolerance. Verify compatibility regarding thermal resistance, stud thread specifications (1/4-28), and polarity configuration. Military qualified versions such as JANTX1N4555B may be used if higher screening levels are required.