Microchip Technology 1N5275A

Overview

1N5275A from Microsemi is a 140 V, ±10% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 0.90 mA test current and 1300 Ω dynamic impedance at 0.25 mA, used for precision voltage reference and overvoltage protection in industrial power supplies and analog instrumentation circuits.

For engineers reviewing the 1N5275A datasheet, 1N5275A pinout, 1N5275A application, or 1N5275A equivalent, this page delivers verified electrical parameters, thermal derating behavior, Zener temperature coefficient (+0.110 %/°C), cathode-band polarity marking, and RoHS-compliant e3 suffix availability - all critical for stable high-voltage regulation design.

Technical Context

This discrete Zener diode operates in reverse breakdown to maintain a stable 140 V reference across wide current (0.1–20 mA) and temperature (−65°C to +175°C) ranges. Its 2600 Ω Zener impedance at IZK = 0.25 mA and 4500 Ω at IZT = 0.90 mA reflect sharp knee characteristics essential for low-noise regulation.

The device uses hermetically sealed glass construction with tin-lead or matte-tin plating, exhibits minimal capacitance (<1.5 pF per Figure 2), and is inherently radiation-hardened per MicroNote 050 - enabling use in aerospace and high-reliability embedded systems where ESD immunity (MIL-STD-750 Method 1020) and long-term stability are required.

Key Specifications

Pinout & Package

DO-35 (DO-204AH) glass axial-leaded package: hermetically sealed cylindrical body, 0.2 g weight, 3/8″ (10 mm) minimum lead length from case for thermal rating compliance, cathode identified by single black band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5275A, the 1N5275B offers tighter voltage control for metrology-critical roles, while the MMBZ5275B enables miniaturization at the cost of derated power handling and altered thermal path - both require revalidation of clamping energy absorption and temperature rise in final design.

Availability

1N5275A is available at Aetrix Electronics and suitable for industrial power supplies, sensor interface protection, and programmable logic controller (PLC) input conditioning requiring stable component supply, long-lifecycle support, and MIL-PRF-19500 screening options (JAN, JANTXV).

Supply support for 1N5275A 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 analog, mixed-signal, and radiation-hardened components for aerospace, defense, and industrial markets.

The 1N52xx series was designed specifically for ruggedized voltage regulation in harsh-environment electronics, emphasizing long-term parametric stability, hermetic sealing, and compatibility with military screening standards.

FAQ

What is the nominal Zener voltage and tolerance of the 1N5275A?

The 1N5275A has a nominal Zener voltage of 140 V with a guaranteed tolerance of ±10% at 25°C, meaning its actual breakdown voltage falls between 126 V and 154 V under standard test conditions (IZT = 0.90 mA). This tolerance is defined by the "A" suffix per JEDEC specification and is confirmed in Microsemi's official datasheet revision D (2005).

What package type and marking does the 1N5275A use?

The 1N5275A uses the DO-35 (DO-204AH) glass axial-leaded package with a black cathode band marking. The part number "1N5275A" is laser-marked or printed directly on the glass body, and polarity must be observed: the banded end is the cathode and must be held positive relative to the anode for Zener regulation.

Can the 1N5275A be used in high-temperature environments?

Yes, the 1N5275A is rated for continuous operation from −65°C to +175°C. Its thermal resistance is 250°C/W junction-to-lead (at 3/8″ lead length) and 310°C/W junction-to-ambient on FR4, enabling reliable function in engine control units, downhole tools, and other high-temperature industrial applications when properly heatsinked.

Is there a RoHS-compliant version of the 1N5275A?

Yes, the RoHS-compliant variant is designated 1N5275Ae3, where the "e3" suffix indicates annealed matte-tin plating compliant with EU RoHS Directive 2011/65/EU. Electrical and thermal specifications remain identical to the standard 1N5275A, and it is solderable per MIL-STD-750 Method 2026.

How does the temperature coefficient affect the 1N5275A's regulation accuracy?

The 1N5275A has a temperature coefficient of +0.110 %/°C, meaning its Zener voltage increases by approximately 154 mV per °C rise above 25°C. For example, at 125°C, VZ shifts to ~147.7 V - a +5.5% deviation. Designers must account for this in high-precision references using thermal compensation or operating within narrower ambient ranges.