1N5278A

Single Zener Diodes Overview

The Microchip Technology 1N5278A is a 0.5 W glass axial-lead Zener diode in the DO-35 package. It provides a nominal Zener voltage of 170 V with a standard tolerance of ±10%. The device operates within a temperature range of -65°C to +175°C and features a maximum reverse current of 100 µA at 123 V. Its electrical characteristics include a Zener impedance of 5500 Ω at IZK = 0.25 mA and a positive voltage temperature coefficient of +0.110 %/°C.

Single Zener Diodes Feature Summary

• Hermetically sealed glass axial-lead construction for reliable operation
• Voltage regulation maintained across broad operating currents and temperatures
• Inherently radiation hard per MicroNote 050
• Minimal capacitance suitable for high-frequency applications

Single Zener Diodes Applications

• Precision voltage reference circuits
• Overvoltage protection networks
• Temperature compensated biasing sources

Single Zener Diodes Procurement Notes

Verify the specific suffix requirements against the design specifications, as the base part number denotes a standard 10% tolerance. Confirm that the manufacturer accepts orders for this legacy component series. Ensure the procurement channel provides traceability documentation required for the intended application environment.

Single Zener Diodes Selection Notes

Select this component when a stable 170 V reference is required in a through-hole assembly. The positive temperature coefficient must be accounted for in thermal designs. Verify that the circuit can sustain the specified power dissipation without exceeding the maximum junction temperature limits under worst-case conditions.

Single Zener Diodes Part Context

This device belongs to the JEDEC registered 1N5221 through 1N5281B series of 0.5 W Zener Voltage Regulators. The series covers a wide voltage selection from 2.4 V to 200 V. The 1N5278A specifically addresses the higher voltage end of the spectrum using standard silicon planar technology housed in a DO-35 glass envelope.

Single Zener Diodes Replacement Considerations

Equivalent parts are available within the same series featuring tighter tolerances (suffixes C or D) or different voltage ratings. Surface mount equivalents exist in the MLL5221 to MLL5281B MELF package family. Military screening levels are accessible via specific prefix identifiers.