Microchip Technology 1N5242BUR-1

Overview

1N5242BUR-1 from Microsemi is a 12 V, 5% tolerance, 500 mW surface-mount Zener diode in DO-213AA (SOD-80/MELF) glass package, designed for precision voltage regulation in low-power analog circuits, reference supplies, and overvoltage protection. It delivers stable 12 V regulation at 20 mA test current with 30 Ω dynamic impedance and operates across –65 °C to +175 °C junction temperature.

For engineers reviewing the 1N5242BUR-1 datasheet, 1N5242BUR-1 pinout, 1N5242BUR-1 application, or 1N5242BUR-1 equivalent, key selection criteria include Zener voltage tolerance (±5%), thermal resistance (250 °C/W), reverse leakage (<1.0 µA at 9.1 V), and MIL-PRF-19500 upscreening eligibility - all critical for industrial and aerospace-grade voltage reference designs.

Technical Context

This device functions as a two-terminal, reverse-biased silicon Zener diode operating in its breakdown region to maintain a stable 12 V output across varying load currents (IZK = 0.25 mA to IZM ≈ 41.7 mA). Its metallurgically bonded glass construction ensures hermetic sealing and radiation hardness per MicroNote 050.

It exhibits a positive temperature coefficient of +0.077 %/°C, indicating increasing Zener voltage with rising temperature - a key design factor when used in temperature-compensated references or bias networks. The 1N5242BUR-1 is not a regulator IC but a passive voltage-reference component requiring external current limiting.

Key Specifications

Pinout & Package

DO-213AA (SOD-80 / MELF) hermetically sealed glass package: cylindrical body with tin-lead or RoHS-compliant matte-tin end-cap terminations; cathode indicated by single band; no polarity-specific PCB footprint orientation required beyond band alignment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5242B-1 and BZX55C12, the 1N5242BUR-1 offers superior thermal performance in SMT layouts and unique radiation-hardened reliability - making it the preferred choice for aerospace, defense, and high-temperature industrial deployments where long-term parametric stability is mandatory.

Availability

1N5242BUR-1 is available at Aetrix Electronics and suitable for industrial sensor conditioning, aerospace power reference, automotive ECM protection, and medical instrumentation bias networks requiring stable component supply across extended temperature and radiation environments.

Supply support for 1N5242BUR-1 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 Corporation (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability, radiation-hardened, and aerospace-grade analog and mixed-signal components.

The 1N52xxBUR-1 series belongs to Microsemi's legacy Zener voltage regulator product line, engineered specifically for applications demanding hermetic packaging, MIL-PRF-19500 compliance, and proven radiation tolerance in mission-critical systems.

FAQ

What is the Zener voltage and tolerance of the 1N5242BUR-1?

The 1N5242BUR-1 has a nominal Zener voltage of 12 V with a tolerance of ±5% at 20 mA test current (I_ZT). This value is guaranteed per the manufacturer's electrical characteristics table and applies across the full operating temperature range when used within specified power and thermal limits. The 1N5242BUR-1 achieves this regulation via controlled avalanche breakdown in its metallurgically bonded silicon junction.

Does the 1N5242BUR-1 support military-grade screening?

Yes, the 1N5242BUR-1 supports upscreening per MIL-PRF-19500 through appropriate reliability level suffixes (e.g., MQ, MX, MV, MSP) added to the base part number. While the commercial "UR-1" variant is un-screened, Microsemi's nomenclature system allows direct ordering of JAN, JANTX, JANTXV, or JANS versions - all sharing the same DO-213AA package and core electrical specs as the 1N5242BUR-1.

What is the maximum power dissipation and thermal resistance of the 1N5242BUR-1?

The 1N5242BUR-1 has a steady-state power dissipation rating of 0.5 W at end cap temperature <125 °C or ambient temperature <50 °C on FR4 board. Its thermal resistance junction-to-ambient (R_θJA) is 250 °C/W under standard mounting conditions. Derating is linear above these temperatures, and R_θJEC is 100 °C/W - enabling accurate thermal modeling when heatsinking via end caps. These values are confirmed in the Maximum Ratings table of the official 1N5242BUR-1 datasheet.

Is the 1N5242BUR-1 RoHS compliant?

Yes, RoHS-compliant versions of the 1N5242BUR-1 are available for commercial-grade use only, identified by the "e3" suffix (e.g., 1N5242BUR-1e3). These variants feature annealed matte-tin plating instead of tin-lead, and meet JEDEC J-STD-609A Class 3 requirements. Non-RoHS versions retain tin-lead terminations and are marked without the "e3" suffix.

What is the temperature coefficient of the 1N5242BUR-1 and how does it affect circuit design?

The 1N5242BUR-1 has a temperature coefficient of +0.077 %/°C, meaning its Zener voltage increases by approximately 9.24 mV per °C rise in junction temperature. This positive TC must be accounted for in precision reference designs - for example, by pairing with a negative-TC component (e.g., forward-biased diode) to achieve near-zero net drift. The coefficient is measured between 25 °C and 125 °C at 20 mA, as defined in the datasheet's Note 3.