1N4554A

Single Zener Diodes Overview

The Microchip Technology 1N4554A is a high-power 50 W Zener diode belonging to the 1N3305–1N3350B and 1N4549–1N4556B series. It provides voltage regulation within a broad range of voltages, specifically offering a nominal Zener voltage of 82.0 V at a test current of 150 mA. The device features a maximum dynamic impedance of 11.0 Ohms and a maximum reverse current of 10 µA at its rated voltage. It operates with a junction temperature range from -65°C to +175°C and utilizes a DO-5 (DO-203AB) package.

Single Zener Diodes Feature Summary

• Hermetically sealed welded construction with internal solder bond for reliability
• Inherently radiation hard design suitable for harsh environments
• ESD nonsensitive per MIL-STD-750 Method 1020
• Standard polarity connects anode to case; reverse polarity available via suffix

Single Zener Diodes Applications

• Voltage regulation in power supplies
• Over-voltage protection circuits
• Reference voltage generation in industrial systems

Single Zener Diodes Procurement Notes

Verify the specific tolerance suffix required for your application, as the 'B' suffix denotes a +/- 5% Zener voltage tolerance. Confirm whether standard or reversed polarity is needed, indicated by an 'R' suffix. Ensure mounting hardware such as insulators or bushings are sourced separately if isolation from the chassis is required. Check for military qualifications like JAN or JANTXV if space-grade screening is necessary.

Single Zener Diodes Selection Notes

Select this component when high power dissipation up to 50 W is required alongside strict environmental resilience. The DO-5 stud mount package facilitates efficient heat transfer to a heatsink. Consider the positive temperature coefficient above 5.6 V for thermal stability in high-voltage applications. Verify that the operating current remains within the specified limits to maintain accurate regulation.

Single Zener Diodes Part Context

This part is manufactured by Microsemi, now part of Microchip Technology, under the Scottsdale Division. It is part of a JEDEC registered series covering voltages from 3.9 V to 200 V. The 1N4554A specifically targets applications requiring robust voltage clamping capabilities in demanding industrial or aerospace settings where hermetic sealing is critical.

Single Zener Diodes Replacement Considerations

Equivalent parts include other 50 W Zener diodes in the DO-5 package with similar voltage ratings. Cross-reference with the 1N33xxB series for identical electrical characteristics. Ensure any substitute matches the thermal resistance and mechanical mounting dimensions of the hexagonal stud.

Single Zener Diodes FAQ

What is the polarity configuration of the 1N4554A?

The standard polarity connects the anode to the case. If reverse polarity (cathode to case) is required, an 'R' suffix must be added to the part number.

How does the 1N4554A handle overtemperature conditions?

The device supports DC power dissipation of 50 watts at a case temperature below 75°C. Above 75°C, the power must be derated at a rate of 0.5 W per degree Celsius.