Microchip Technology 1N971BE3

Overview

1N971BE3 from Microsemi is a silicon 500 mW axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 27 V nominal Zener voltage at 4.6 mA test current, with ±5% tolerance (B suffix), +0.090 %/°C temperature coefficient, and 750 Ω maximum Zener impedance at I_ZT. It regulates voltage in low-power reference and protection circuits across industrial and aerospace systems.

For engineers reviewing the 1N971BE3 datasheet, 1N971BE3 pinout, 1N971BE3 application, or 1N971BE3 equivalent, key selection factors include its 27 V regulation point, 4.6 mA Zener test current, 750 Ω dynamic impedance, -65°C to +175°C operating range, and RoHS-compliant matte-tin plating - critical for stable biasing, overvoltage clamping, and precision voltage referencing in harsh-environment designs.

Technical Context

The 1N971BE3 operates as a reverse-biased voltage reference diode, maintaining stable 27 V regulation over 13 mA to 15 mA DC Zener current (I_ZM = 13 mA, I_ZSM = 70 mA surge). Its +0.090 %/°C temperature coefficient ensures predictable drift in thermal-varying environments, while its 750 Ω Zener impedance at 4.6 mA reflects moderate dynamic resistance suitable for non-critical analog references.

Designed for axial-leaded through-hole mounting, the device uses hermetically sealed glass DO-35 construction with cathode band marking, tin-lead or RoHS-compliant matte-tin terminations, and meets MIL-STD-750 ESD immunity (Method 1020). Thermal resistance is 250 °C/W junction-to-lead at 10 mm lead length.

Key Specifications

Pinout & Package

Package: DO-35 (DO-204AH), hermetically sealed glass axial-leaded case with cathode indicated by colored band. Terminations are RoHS-compliant annealed matte-tin per MIL-STD-750 Method 2026.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N971B and MMBZ5256BS-7-F, the 1N971BE3 uniquely combines 500 mW power handling, DO-35 mechanical ruggedness, -65°C to +175°C operation, and RoHS compliance - making it irreplaceable for high-reliability through-hole Zener applications where thermal margin and regulatory compliance are non-negotiable.

Availability

1N971BE3 is available at Aetrix Electronics and suitable for industrial power supply monitoring, aerospace voltage reference, and automotive sensor signal conditioning requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for 1N971BE3 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 defense, aerospace, and industrial markets.

The 1N971BE3 belongs to Microsemi's legacy JEDEC-registered 1N957B–1N992B Zener series, designed specifically for stable, low-cost, high-temperature voltage regulation in mission-critical through-hole applications.

FAQ

What is the Zener voltage tolerance of the 1N971BE3?

The 1N971BE3 has a nominal Zener voltage of 27 V with a ±5% tolerance, as indicated by the "B" suffix per JEDEC standard. This means its actual regulation voltage falls between 25.65 V and 28.35 V at 25°C and 4.6 mA test current. The tolerance remains valid across the full -65°C to +175°C operating range, though voltage drift follows the +0.090 %/°C temperature coefficient.

Does the 1N971BE3 meet RoHS requirements?

Yes, the "e3" suffix in 1N971BE3 explicitly denotes RoHS compliance per Directive 2011/65/EU. The device uses annealed matte-tin plating instead of traditional tin-lead, verified per MIL-STD-750 Method 2026. No lead, cadmium, mercury, hexavalent chromium, PBB, or PBDE substances exceed allowable limits.

What is the maximum continuous Zener current for the 1N971BE3?

The maximum DC Zener current (I_ZM) for the 1N971BE3 is 13 mA. This value is calculated to limit power dissipation to 400 mW at a 75°C lead temperature measured 3/8″ from the body. At ambient temperatures below 25°C on FR4 board, the device supports up to 500 mW steady-state dissipation, but thermal design must respect the 250 °C/W junction-to-lead resistance.

How is polarity marked on the 1N971BE3?

The 1N971BE3 uses a cathode band - a single colored ring near one end of the DO-35 glass body - to indicate the cathode terminal. For proper Zener regulation, the banded end must be held at a higher potential than the anode (non-banded) end. Forward voltage is guaranteed ≤1.3 V at 200 mA, confirming correct orientation during functional testing.

Can the 1N971BE3 replace the 1N971B in existing designs?

Yes, the 1N971BE3 is a direct RoHS-compliant replacement for the 1N971B, sharing identical electrical specifications, DO-35 package dimensions, and thermal characteristics. The only difference is matte-tin plating versus tin-lead terminations. No PCB layout or schematic changes are needed, though solder profile must be adjusted for lead-free reflow if used in SMT assembly.