Microchip Technology 1N5281A

Overview

1N5281A from Microsemi is a 200 V, ±10% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for operation from −65 °C to +175 °C, with 0.1 μA max reverse current at 160 V and 10 Ω max zener impedance at 0.25 mA, used for precision voltage regulation in power supply reference circuits.

For engineers reviewing the 1N5281A datasheet, 1N5281A pinout, 1N5281A application, or 1N5281A equivalent, key selection factors include its 200 V nominal zener voltage, 10% tolerance (A suffix), 0.1 μA leakage at VR = 160 V, temperature coefficient of +0.110 %/°C, and DO-35 mechanical compatibility in high-reliability analog and aerospace power conditioning designs.

Technical Context

The 1N5281A operates as a two-terminal voltage reference device, conducting in reverse breakdown with sharp knee characteristics verified per JEDEC test methods. Its zener impedance is measured at IZK = 0.25 mA and ac-superimposed 10% IZK, ensuring stable regulation under low-current bias conditions.

It exhibits a positive temperature coefficient of +0.110 %/°C over 25–125 °C, consistent across the 1N5276A–1N5281A subgroup, and is specified with thermal resistance of 250 °C/W junction-to-lead at 10 mm lead length-critical for derating in sealed or high-ambient environments.

Key Specifications

Pinout & Package

DO-35 (DO-204AH) hermetically sealed glass axial-lead package with cathode band marking; leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener voltage regulation applications.

Compared with 1N5281B and MMBZ5281B, the 1N5281A offers lowest cost and highest temperature capability among 200 V Zeners, but requires axial-lead assembly and accepts wider initial tolerance-making it optimal for cost-sensitive, high-temp, through-hole designs where post-calibration compensates for ±10% spread.

Availability

1N5281A is available at Aetrix Electronics and suitable for high-reliability power supply reference, aerospace voltage monitoring, and industrial sensor excitation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 1N5281A includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability, radiation-hardened, and high-voltage analog components for defense, aerospace, and industrial markets.

The 1N52xx series was designed specifically for ruggedized voltage regulation in mission-critical systems where hermetic packaging, wide temperature operation, and JEDEC-standard parametric guarantees are mandatory.

FAQ

What is the nominal zener voltage and tolerance of the 1N5281A?

The 1N5281A has a nominal zener voltage of 200 V with a tolerance of ±10%, as indicated by the "A" suffix per Microsemi's documentation. This means the actual breakdown voltage falls between 180 V and 220 V at 25 °C under test current IZT = 0.65 mA. The 1N5281A is not rated for tighter tolerances-those require the "B" (±5%), "C" (±2%), or "D" (±1%) suffix variants.

What package type and mounting configuration does the 1N5281A use?

The 1N5281A uses the DO-35 (also designated DO-204AH) hermetically sealed glass axial-lead package. It features flexible axial-lead terminals with cathode identified by a painted band; the banded end must be held positive relative to the anode for proper Zener operation. Lead finish is tin-lead or RoHS-compliant matte tin, qualified per MIL-STD-750 Method 2026.

What is the maximum reverse leakage current specification for the 1N5281A?

The 1N5281A specifies a maximum reverse current (IR) of 0.1 μA at VR = 160 V, as confirmed in the Electrical Characteristics table on page 2 of the Microsemi datasheet. This low leakage supports high-impedance bias networks and ensures minimal power loss in standby or low-current regulation modes.

How does the temperature coefficient of the 1N5281A affect its performance?

The 1N5281A has a temperature coefficient (αVZ) of +0.110 %/°C, measured from 25 °C to 125 °C at rated IZT. This means its zener voltage increases by approximately 0.22 V per 10 °C rise-critical for precision references. System designers must either compensate in firmware or select this part only where drift within ±2.2 V over 100 °C is acceptable.

Can the 1N5281A be used in military or aerospace applications?

Yes-the 1N5281A is JEDEC-registered and supports optional military screening per MIL-PRF-19500 (JAN, JANTX, JANTXV, JANS) when ordered with appropriate prefixes and the "-1" internal bond suffix. Its DO-35 hermetic glass package, −65 °C to +175 °C operating range, and radiation hardness per MicroNote 050 make it suitable for qualified aerospace and defense platforms.