Microchip Technology 1N5268B/TR

Overview

1N5268B/TR from Microsemi is a 500 mW, 82 V, ±5% tolerance glass axial-lead Zener diode in DO-35 (DO-204AH) package, designed for precision voltage regulation and reference applications across industrial power supplies, instrumentation, and overvoltage protection circuits.

For engineers reviewing the 1N5268B/TR datasheet, 1N5268B/TR pinout, 1N5268B/TR application, or 1N5268B/TR equivalent, this part delivers stable 82 V Zener regulation at 1.5 mA test current with 2000 Ω dynamic impedance, low temperature coefficient (+0.098 %/°C), and operation from –65 °C to +175 °C - critical for high-reliability analog and aerospace-grade designs.

Technical Context

The 1N5268B/TR operates as a two-terminal voltage reference device, relying on controlled reverse-biased avalanche breakdown to maintain a stable 82 V output across a wide current range (0.25 mA to 1.5 mA). Its DO-35 glass package provides hermetic sealing and inherent radiation hardness per MicroNote 050.

It exhibits minimal capacitance (≈1.5 pF typical at 0 V, per Figure 2), low ESD sensitivity (MIL-STD-750 Method 1020), and thermal resistance of 250 °C/W junction-to-lead at 3/8″ lead length - enabling reliable performance in thermally constrained PCB layouts without heatsinking.

Key Specifications

Pinout & Package

Hermetically sealed DO-35 (DO-204AH) glass axial-leaded package with cathode indicated by a single black 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 voltage reference applications.

Compared with 1N5268B/TR, the 1N5268B lacks tape-and-reel convenience but offers identical performance, while MMSZ5268B-TP trades axial-mount flexibility for SMT compatibility at marginally higher impedance - making 1N5268B/TR optimal for through-hole production requiring traceable, automated feed.

Availability

1N5268B/TR is available at Aetrix Electronics and suitable for industrial power supply regulation, aerospace voltage reference, and overvoltage protection applications requiring stable component supply, long-term lifecycle support, and guaranteed DO-35 packaging integrity.

Supply support for 1N5268B/TR 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 components for defense, aerospace, and industrial markets.

The 1N52xxB series was developed to deliver JEDEC-standardized, high-stability Zener references for mission-critical voltage regulation where long-term parametric consistency and extreme environmental resilience are mandatory.

FAQ

What is the nominal Zener voltage and tolerance of the 1N5268B/TR?

The 1N5268B/TR has a nominal Zener voltage of 82 V with a guaranteed tolerance of ±5%, as indicated by the "B" suffix. This means its actual breakdown voltage falls between 77.9 V and 86.1 V when measured at 1.5 mA test current and 25 °C ambient temperature. The 1N5268B/TR meets JEDEC specifications for the 1N52xxB family and is tested to ensure compliance across its full operating temperature range.

What package type and marking does the 1N5268B/TR use?

The 1N5268B/TR uses the DO-35 (DO-204AH) hermetically sealed glass axial-leaded package, with cathode identified by a single black band. It is marked with the full part number "1N5268B" on the glass body. The "TR" suffix confirms tape-and-reel packaging per EIA-296 standard, enabling automated pick-and-place assembly. Lead finish is RoHS-compliant matte tin unless otherwise specified.

How does the 1N5268B/TR perform at elevated temperatures?

The 1N5268B/TR is rated for continuous operation from –65 °C to +175 °C. Its Zener voltage exhibits a temperature coefficient of +0.098 %/°C, meaning V_Z increases predictably with temperature. At 125 °C, the shift is approximately +9.8 V relative to 25 °C - a known, linear deviation that can be compensated in precision circuits. Thermal resistance is 250 °C/W junction-to-lead at 3/8″ lead length.

Is the 1N5268B/TR suitable for high-reliability or radiation-exposed environments?

Yes - the 1N5268B/TR is inherently radiation-hardened per MicroNote 050 and qualified for use in aerospace and defense applications. It is nonsensitive to ESD (MIL-STD-750 Method 1020) and available with military screening prefixes (e.g., MV, MSP) when ordered with the "-1" suffix. Its glass DO-35 construction provides hermetic sealing, eliminating moisture-induced failure mechanisms common in plastic-packaged alternatives.

What is the maximum reverse current specification for the 1N5268B/TR?

The 1N5268B/TR has a maximum reverse current (I_R) of 0.1 μA when measured at 66 V (80% of nominal V_Z). This ultra-low leakage ensures minimal power loss in high-impedance bias networks and preserves accuracy in precision reference circuits. The value is guaranteed across the full –65 °C to +175 °C operating range and reflects strict process control in Microsemi's Scottsdale fabrication line.