Microchip Technology 1N5268BE3

Overview

1N5268BE3 from Microsemi is a 500 mW, 82 V, ±5% tolerance glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for -65°C to +175°C operation, with 1.5 V max forward voltage at 200 mA and 2000 Ω max Zener impedance at 0.25 mA test current. It serves as a precision voltage reference in low-power analog circuits and overvoltage protection clamps.

For engineers reviewing the 1N5268BE3 datasheet, 1N5268BE3 pinout, 1N5268BE3 application, or 1N5268BE3 equivalent, key selection criteria include its 82 V nominal Zener voltage, ±5% tolerance (B suffix), RoHS-compliant matte-tin plating (e3 suffix), and thermal resistance of 250 °C/W junction-to-lead at 10 mm lead length.

Technical Context

This discrete Zener diode operates in reverse breakdown to maintain stable voltage across a broad current range (IZK = 0.25 mA, IZT = 1.5 mA). Its regulation performance is characterized by temperature coefficient αVZ = +0.098 %/°C (measured from 25°C to 125°C at rated IZT), and it exhibits minimal capacitance per Figure 2 of the datasheet.

The device uses hermetically sealed glass construction with cathode band polarity marking, supports soldering at 260°C for 10 s, and is nonsensitive to ESD per MIL-STD-750 Method 1020. Its mechanical design enables flexible axial-lead mounting on FR4 PCBs with defined thermal pad layout.

Key Specifications

Pinout & Package

DO-35 (DO-204AH) glass axial-leaded package with cathode indicated by a single color band; leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026. Weight: 0.2 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5268BE3, the 1N5268B offers identical electrical performance but lacks RoHS compliance, while MMBZ5268B provides identical specs in SOT-23 format-enabling miniaturization at the cost of axial-lead compatibility and requiring thermal redesign for equivalent power handling.

Availability

1N5268BE3 is available at Aetrix Electronics and suitable for industrial power supply monitoring, aerospace voltage reference, and downhole sensor biasing requiring stable component supply with full traceability and extended temperature qualification.

Supply support for 1N5268BE3 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-temperature analog and mixed-signal components.

The 1N52xxB series was designed for precision voltage regulation in mission-critical systems where wide temperature operation, ESD immunity, and long-term parametric stability are essential.

FAQ

What is the nominal Zener voltage and tolerance of the 1N5268BE3?

The 1N5268BE3 has a nominal Zener voltage of 82 V with a tolerance of ±5%, as indicated by the "B" suffix in the part number. This tolerance is guaranteed across the full operating temperature range of -65°C to +175°C, and the device is tested per JEDEC standards to ensure compliance on all six key parameters including VZ, IR, VF, ZZT, ZZK, and temperature coefficient.

Does the 1N5268BE3 require heatsinking in typical applications?

The 1N5268BE3 does not require external heatsinking in most applications due to its 500 mW power rating and low thermal resistance of 250 °C/W junction-to-lead at 10 mm lead length. However, when operated near full power at elevated ambient temperatures, PCB copper area per the datasheet's FR4 mounting recommendation (4 mm² pads, 1 mm track width, 25 mm length) is necessary to maintain safe junction temperature.

How is polarity marked on the 1N5268BE3, and what is its correct biasing configuration?

The 1N5268BE3 uses a cathode band to indicate polarity: the banded end is the cathode and must be held at a higher potential than the anode to achieve Zener breakdown regulation. When used as a voltage reference or clamp, the cathode connects to the voltage rail being regulated, and the anode connects to ground or a lower reference potential.

Is the 1N5268BE3 suitable for high-reliability aerospace applications?

Yes, the 1N5268BE3 is inherently radiation-hardened per MicroNote 050 and qualified for operation from -65°C to +175°C. While not pre-screened to JAN/JANTX levels, its base DO-35 construction and process make it a candidate for non-military aerospace applications where radiation tolerance and extended temperature range are required without formal MIL-PRF-19500 screening.

What is the maximum forward voltage specification for the 1N5268BE3?

The 1N5268BE3 has a maximum forward voltage of 1.5 V at 200 mA forward current, as specified in the Maximum Ratings table. This parameter is relevant when the device is used in forward conduction-such as in dual-direction transient protection configurations-or during initial power-up sequencing before Zener breakdown is established.