Microchip Technology 1N5237A

Overview

1N5237A from Microsemi is a 500 mW, 8.2 V ±10% glass axial-lead Zener diode in DO-35 (DO-204AH) package, designed for precision voltage regulation and reference applications in low-power analog circuits, power supply feedback paths, and overvoltage protection. It operates across –65°C to +175°C with 8 Ω dynamic impedance at 20 mA test current and 3.0 Ω knee impedance at 0.25 mA.

For engineers reviewing the 1N5237A datasheet, 1N5237A pinout, 1N5237A application, or 1N5237A equivalent, key selection criteria include its 8.2 V nominal Zener voltage, ±10% tolerance (A suffix), 500 mW power rating at 25°C, DO-35 mechanical form factor, and temperature coefficient of +0.062 %/°C - all critical for stable biasing and reference design under thermal stress.

Technical Context

The 1N5237A functions as a two-terminal reverse-biased voltage reference, maintaining regulation across 1.0 mA to 20 mA operating current. Its Zener breakdown mechanism delivers predictable voltage stabilization with minimal capacitance (<2.0 pF typical) and inherent radiation hardness per MicroNote 050.

It exhibits a positive temperature coefficient (+0.062 %/°C), indicating increasing V_Z with rising junction temperature - a key consideration for high-temperature industrial and aerospace designs where thermal drift must be compensated in closed-loop systems.

Key Specifications

Pinout & Package

DO-35 (DO-204AH) hermetically sealed glass axial-leaded package with cathode indicated by colored band; leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5237A, 1N4738A offers higher power and tighter tolerance but requires board redesign for DO-41; MMBZ5237BS enables miniaturization and automation at the cost of thermal headroom and absolute stability under high ambient conditions.

Availability

1N5237A is available at Aetrix Electronics and suitable for industrial control systems, aerospace avionics, and automotive engine management units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 1N5237A 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 1N52xx series was engineered for ruggedized voltage reference applications demanding JEDEC-standardized performance, extreme temperature resilience, and proven field reliability in mission-critical systems.

FAQ

What is the nominal Zener voltage and tolerance of the 1N5237A?

The 1N5237A has a nominal Zener voltage of 8.2 V with a tolerance of ±10%, as indicated by the "A" suffix per Microsemi's documentation. This tolerance is guaranteed under standard test conditions (I_ZT = 20 mA, T_A = 25°C), and the device meets JEDEC registration requirements for the 1N52xx family. The 1N5237A is not rated for tighter tolerances like ±5% (B suffix) or ±1% (D suffix).

What package type and marking does the 1N5237A use?

The 1N5237A uses the DO-35 (DO-204AH) glass axial-leaded package with cathode identified by a visible color band. The device is marked with its full part number "1N5237A" on the body. Lead finish is either tin-lead or RoHS-compliant matte-tin plating, qualified per MIL-STD-750 Method 2026 for solderability.

What is the maximum power dissipation and thermal derating behavior of the 1N5237A?

The 1N5237A is rated for 500 mW at 25°C ambient or lead temperature (TL < 50°C at 3/8″ from body). Power derates linearly to zero at 175°C, with thermal resistance of 250°C/W junction-to-lead (3/8″ lead length) or 310°C/W junction-to-ambient on FR4. Derating curves are documented in Figure 1 of the official Microsemi datasheet for the 1N5221–1N5281B series.

How does the temperature coefficient of the 1N5237A affect its performance in high-temperature environments?

The 1N5237A has a temperature coefficient of +0.062 %/°C, meaning its Zener voltage increases by approximately 5.1 mV per °C rise above 25°C. In applications above 85°C, this drift must be accounted for in reference accuracy budgets - for example, at 125°C, V_Z rises by ~6.2 V × 0.00062 × 100 ≈ 51 mV. The 1N5237A remains functional up to +175°C but requires system-level compensation for precision use.

Is the 1N5237A suitable for ESD-sensitive assembly environments?

Yes, the 1N5237A is nonsensitive to electrostatic discharge per MIL-STD-750 Method 1020, eliminating the need for special ESD handling procedures during manual or automated assembly. This characteristic is confirmed in the Features section of the Microsemi datasheet and applies across all 1N52xx devices regardless of suffix. No external ESD protection is required solely due to handling risks for the 1N5237A.