Microchip Technology 1N5267A

Overview

1N5267A from Microsemi is a 75 V, ±10% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 1.7 mA test current, 270 Ω dynamic impedance at 0.25 mA, and -65°C to +175°C operating temperature range; used for precision voltage reference and overvoltage protection in industrial power supplies.

For engineers reviewing the 1N5267A datasheet, 1N5267A pinout, 1N5267A application, or 1N5267A equivalent, key selection criteria include Zener voltage stability across temperature, low leakage at 57 V reverse bias, thermal resistance of 250 °C/W (junction-to-lead), and compatibility with manual or wave soldering at 260 °C for 10 s.

Technical Context

This discrete Zener diode operates in reverse breakdown mode with cathode-banded polarity, requiring the banded end to be held positive relative to the anode for regulation. Its 75 V nominal Zener voltage exhibits +0.098 %/°C temperature coefficient above 25 °C, measured at rated I_ZT = 1.7 mA.

It delivers stable regulation over 0.25 mA to 10 mA operating current, with maximum reverse current of 0.1 μA at 57 V and forward voltage ≤1.5 V at 200 mA - enabling use in low-power bias networks and voltage-clamp circuits where minimal parasitic capacitance and ESD insensitivity are critical.

Key Specifications

Pinout & Package

DO-35 (DO-204AH) hermetically sealed glass axial-leaded package with tin-lead or RoHS-compliant matte-tin plating; cathode identified by single black band; weight 0.2 g; case dimensions per Microsemi drawing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4744A and BZX55C75, the 1N5267A offers JEDEC-registered consistency, military screening options (MQ/MX/MV prefixes), and proven radiation hardness - making it uniquely suitable for high-reliability 75 V reference applications where qualification traceability and TID tolerance are mandatory.

Availability

1N5267A is available at Aetrix Electronics and suitable for industrial power supplies, aerospace voltage clamps, military screening reference circuits, and high-temperature downhole instrumentation requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for 1N5267A 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 and mixed-signal components for aerospace, defense, and industrial markets.

The 1N52xx series was designed specifically for precision voltage reference and overvoltage protection in mission-critical systems requiring extended temperature operation, radiation tolerance, and MIL-PRF-19500 qualification pathways.

FAQ

What is the Zener voltage tolerance for 1N5267A?

The 1N5267A has a nominal Zener voltage of 75 V with a guaranteed tolerance of ±10%, as indicated by the "A" suffix per Microsemi's documentation. This tolerance applies to the parameter set including V_Z, I_R, and V_F, and is verified under JEDEC-standard test conditions at 25 °C with 1.7 mA test current. The 1N5267A does not carry tighter C (±2%) or D (±1%) tolerances.

Can 1N5267A be used in surface-mount designs?

No - the 1N5267A is packaged exclusively in the axial-leaded DO-35 (DO-204AH) glass body and is not a surface-mount device. For SMT equivalents, Microsemi offers the MLL5267B in DO-213AA (MELF) package; however, that part uses a "B" suffix and has ±5% tolerance, differing from the 1N5267A's ±10% spec and axial form factor.

What is the maximum reverse voltage before breakdown for 1N5267A?

The 1N5267A begins Zener breakdown at its nominal voltage of 75 V, with regulation specified between 0.25 mA and 10 mA. Its maximum non-breakdown reverse voltage is defined by the test condition for leakage current: 57 V (80% of V_Z), where reverse current is guaranteed ≤0.1 μA. Operation above 75 V risks uncontrolled conduction unless current-limited.

Does 1N5267A require heatsinking in standard PCB layouts?

No additional heatsinking is required for 1N5267A at ≤500 mW dissipation within its 25 °C ambient rating. When mounted on FR4 with 4 mm² copper pads and 1 mm track width, its thermal resistance is 310 °C/W junction-to-ambient; at 25 °C ambient and 500 mW power, junction temperature reaches ~177.5 °C - still below the 175 °C absolute max. Derating per Figure 1 is mandatory above 25 °C.

Is 1N5267A RoHS compliant?

Yes - the 1N5267A is available in RoHS-compliant version when ordered with the "e3" suffix (e.g., 1N5267Ae3), featuring annealed matte-tin plating per MIL-STD-750 Method 2026. Standard 1N5267A uses tin-lead plating; RoHS compliance must be explicitly specified in the order code to ensure correct finish delivery.