Microchip Technology 1N5268A

Overview

1N5268A from Microsemi is a 500 mW, 82 V, ±10% tolerance glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for operation from −65 °C to +175 °C, with 1.5 V max forward voltage at 200 mA and 2000 Ω max zener impedance at 0.25 mA test current - used for precision voltage reference and overvoltage protection in industrial power supplies.

For engineers reviewing the 1N5268A datasheet, 1N5268A pinout, 1N5268A application, or 1N5268A equivalent, key selection criteria include its 82 V nominal zener voltage, ±10% tolerance (A suffix), 500 mW power rating at 25 °C, DO-35 glass package thermal resistance (250 °C/W junction-to-lead), and temperature coefficient of +0.098 %/°C.

Technical Context

The 1N5268A operates as a reverse-biased voltage-regulating diode with sharp breakdown knee verified per MicroNote 202; its zener impedance is measured at two points (IZK = 0.25 mA and IZT = 1.5 mA) to ensure stability under varying load conditions.

It exhibits minimal capacitance across its operating voltage range (see Figure 2), supports soldering at 260 °C for 10 s, and maintains regulation over a wide temperature span due to its inherent radiation hardness and −65 °C to +175 °C storage/operating range.

Key Specifications

Pinout & Package

DO-35 (DO-204AH) hermetically sealed glass axial-lead package with cathode indicated by band; diode operated with banded end positive relative to opposite end for zener regulation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5268B and MMBZ5268AL, the 1N5268A offers the broadest thermal operating range (−65 °C to +175 °C), highest power rating (500 mW vs. 250 mW), and proven hermetic DO-35 reliability - making it optimal for high-reliability, high-temperature, or legacy through-hole designs.

Availability

1N5268A is available at Aetrix Electronics and suitable for industrial power supply reference, overvoltage protection clamp, and high-temperature sensor biasing requiring stable component supply across extended temperature and lifecycle demands.

Supply support for 1N5268A 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, RF, and radiation-hardened components for aerospace, defense, and industrial markets.

The 1N52xx series was designed specifically for robust, low-cost, high-temperature voltage regulation in mission-critical systems where long-term stability and JEDEC-standard compliance are mandatory.

FAQ

What is the nominal zener voltage and tolerance of the 1N5268A?

The 1N5268A has a nominal zener voltage of 82 V with a tolerance of ±10%, as indicated by the "A" suffix per Microsemi's documentation. This tolerance applies under standard test conditions (25 °C, IZT = 1.5 mA), and the device is JEDEC-registered for guaranteed VZ, IR, and VF limits. The 1N5268A is not rated for tighter tolerances like ±5% (B suffix) or ±1% (D suffix).

What package type and mounting configuration does the 1N5268A use?

The 1N5268A uses the DO-35 (DO-204AH) hermetically sealed glass axial-lead package. It is mounted via through-hole insertion with flexible lead forming; the cathode is marked by a band on the glass body and must be held at higher potential than the anode for zener regulation. Lead length from the body is specified at ≥3/8 inch (10 mm) for thermal rating compliance.

What is the maximum power dissipation and thermal resistance of the 1N5268A?

The 1N5268A has a maximum power dissipation of 500 mW at 25 °C, derating linearly above 50 °C lead temperature. Its thermal resistance is 250 °C/W junction-to-lead (at 3/8 inch lead length) or 310 °C/W junction-to-ambient on FR4 board. These values define safe continuous operation limits and inform heatsinking decisions in high-power-density designs.

Does the 1N5268A have radiation hardness or ESD immunity specifications?

Yes, the 1N5268A is inherently radiation hard per MicroNote 050 and nonsensitive to ESD per MIL-STD-750 Method 1020. These characteristics are built into the DO-35 glass construction and process, requiring no additional shielding or handling controls. The 1N5268A is also available in MIL-PRF-19500 screened versions (e.g., JANTXV-1N5268A) for enhanced reliability assurance.

How does the temperature coefficient affect the 1N5268A's performance in real-world applications?

The 1N5268A has a temperature coefficient of +0.098 %/°C, meaning its zener voltage increases by approximately 80.6 mV per °C rise above 25 °C. This drift must be accounted for in precision references; however, the 1N5268A's wide −65 °C to +175 °C operating range ensures functionality in extreme environments where alternatives may fail or require external compensation.