Microchip Technology 1N5276B/TR

Overview

1N5276B/TR from Microsemi is a 150 V, ±5% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for operation from −65 °C to +175 °C, with 10 μA maximum reverse current at 120 V and 108 V nominal regulation at 0.85 mA test current. It serves as a precision voltage reference in low-power analog monitoring circuits.

For engineers reviewing the 1N5276B/TR datasheet, 1N5276B/TR pinout, 1N5276B/TR application, or 1N5276B/TR equivalent, key selection criteria include its 150 V Zener voltage, tight ±5% tolerance (B suffix), 500 mW power rating, DO-35 axial package, and temperature coefficient of +0.110 %/°C - all critical for stable high-voltage reference design in aerospace and industrial control systems.

Technical Context

This Zener diode operates in reverse breakdown mode with a sharp knee at IZK = 0.25 mA, where dynamic impedance is measured at 5000 Ω. Its regulation stability over temperature is governed by a positive voltage temperature coefficient of +0.110 %/°C, consistent across the 1N5271–1N5281B series.

The device uses hermetically sealed glass construction with tin-lead or RoHS-compliant matte-tin plating, enabling reliable operation under thermal cycling and radiation exposure per MicroNote 050. Polarity is marked by a cathode band; regulation requires the banded end to be biased positive relative to the anode.

Key Specifications

Pinout & Package

DO-35 (DO-204AH) glass axial-leaded package with cathode indicated by a single black band; leads are tinned copper, solderable per MIL-STD-750 Method 2026. Weight: 0.2 g. Mounting requires ≥10 mm lead length from body for rated thermal resistance (250 °C/W junction-to-lead).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5276A/TR and MMBZ5276B-TP, the 1N5276B/TR delivers tighter voltage tolerance in a rugged, axial-leaded, radiation-hardened package - making it optimal for high-reliability, through-hole, high-temperature applications where long-term stability and mechanical robustness are prioritized over assembly automation.

Availability

1N5276B/TR is available at Aetrix Electronics and suitable for high-voltage reference, aerospace sensor biasing, and industrial PLC analog input conditioning requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 1N5276B/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-voltage analog components for aerospace, defense, and industrial markets.

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

FAQ

What is the Zener voltage tolerance of the 1N5276B/TR?

The 1N5276B/TR has a nominal Zener voltage of 150 V with a guaranteed tolerance of ±5%, as indicated by the "B" suffix per JEDEC specification. This tolerance is verified at 0.85 mA test current and 25 °C ambient, and remains valid across the full −65 °C to +175 °C operating range per Microsemi's characterization data.

Does the 1N5276B/TR require heatsinking in standard PCB mounting?

No, the 1N5276B/TR does not require external heatsinking when operated at ≤500 mW within its derated power envelope. At 25 °C ambient, full-rated power is supported; above that, linear derating applies - e.g., 375 mW at 75 °C - based on its 250 °C/W junction-to-lead thermal resistance with ≥10 mm lead length from the DO-35 body.

Is the 1N5276B/TR suitable for space-grade applications?

Yes, the 1N5276B/TR is inherently radiation-hardened per MicroNote 050 and qualifies for space applications when procured with appropriate screening (e.g., JANS or JANTXV prefixes). Its glass DO-35 construction, −65 °C to +175 °C rating, and ESD immunity make it suitable for satellite power monitoring and payload sensor biasing where TID resilience is required.

How is polarity marked on the 1N5276B/TR?

The 1N5276B/TR uses a single black cathode band on the glass body to indicate polarity. For proper Zener regulation, the banded (cathode) end must be biased positive relative to the unmarked (anode) end. This marking conforms to JEDEC DO-35 standards and is visible under standard visual inspection.

What is the maximum reverse leakage current for the 1N5276B/TR?

The 1N5276B/TR specifies a maximum reverse current (IR) of 10 μA at VR = 120 V, measured after 20 seconds of thermal stabilization per Note 1 in the datasheet. This low leakage supports high-impedance bias networks and minimizes power loss in always-on reference circuits.