Microchip Technology 1N5246A

Overview

1N5246A from Microsemi is a 16 V, ±10% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 7.8 mA test current, 600 Ω maximum zener impedance at IZK, and operating from –65°C to +175°C. It serves as a precision voltage reference or shunt regulator in low-power analog circuits, power supply feedback paths, and overvoltage protection.

For engineers reviewing the 1N5246A datasheet, 1N5246A pinout, 1N5246A application, or 1N5246A equivalent, key selection criteria include its 16 V nominal zener voltage, ±10% tolerance (A suffix), 600 Ω dynamic impedance, thermal resistance of 250 °C/W junction-to-lead, and DO-35 mechanical compatibility with axial-leaded PCB layouts.

Technical Context

The 1N5246A operates as a silicon planar Zener diode with controlled reverse breakdown at 16 V under 7.8 mA test current. Its zener impedance is specified at both IZT (600 Ω max) and IZK = 0.25 mA (600 Ω max), confirming stable regulation across low-current conditions.

It exhibits a positive temperature coefficient of +0.083 %/°C (25°C to 125°C), indicating increasing VZ with temperature - critical for thermal drift compensation in reference designs. The device is hermetically sealed in glass, nonsensitive to ESD per MIL-STD-750 Method 1020, and radiation-hardened per MicroNote 050.

Key Specifications

Pinout & Package

DO-35 (DO-204AH) glass axial-leaded package: hermetically sealed cylindrical glass body with tinned copper alloy leads; cathode identified by single black band; polarity must be observed - banded end is cathode (positive during Zener operation).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5246B and MMBZ5246BS, the 1N5246A offers the lowest-cost solution for general-purpose 16 V regulation where ±10% tolerance is acceptable and axial-leaded mounting is preferred; it delivers higher power headroom than the SOT-23 variant while maintaining JEDEC DO-35 compatibility.

Availability

1N5246A is available at Aetrix Electronics and suitable for voltage reference design, overvoltage protection, and power supply feedback applications requiring stable component supply across industrial, aerospace, and test equipment programs.

Supply support for 1N5246A 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 1N52xxA/B series was designed specifically for robust, low-cost, through-hole Zener regulation in mission-critical systems where extended temperature range, ESD immunity, and long-term stability are mandatory.

FAQ

What is the nominal zener voltage and tolerance of the 1N5246A?

The 1N5246A has a nominal zener voltage of 16 V with a ±10% tolerance, as indicated by the "A" suffix per Microsemi's documentation. This means its actual breakdown voltage falls between 14.4 V and 17.6 V at 25°C under 7.8 mA test current. The tolerance is guaranteed per JEDEC specification for this suffix, and the 1N5246A is not rated for tighter tolerances like ±5% (B suffix) or ±1% (D suffix).

What package type and mounting style does the 1N5246A use?

The 1N5246A uses the DO-35 (also designated DO-204AH) glass axial-leaded package. It features a hermetically sealed glass body with two tinned copper alloy leads extending axially; the cathode is marked by a single black band. Mounting requires axial insertion into PCB holes with 3/8 inch (10 mm) minimum lead length from the body for thermal performance compliance.

What is the maximum power dissipation and thermal resistance of the 1N5246A?

The 1N5246A has a maximum power dissipation of 500 mW at 25°C ambient or lead temperature, derating linearly above that temperature. Its thermal resistance is 250 °C/W junction-to-lead (measured at 3/8 inch lead length) and 310 °C/W junction-to-ambient on FR4 board with specified copper pad geometry. These values define safe operating area boundaries for continuous DC or pulsed operation.

Does the 1N5246A have radiation hardness or ESD immunity specifications?

Yes, the 1N5246A is inherently radiation-hardened per MicroNote 050 and is nonsensitive to electrostatic discharge per MIL-STD-750 Method 1020. These characteristics are intrinsic to its planar silicon process and glass package construction, making it suitable for high-reliability applications in aerospace, downhole tools, and military electronics without requiring external hardening measures.

How does the temperature coefficient of the 1N5246A affect its regulation performance?

The 1N5246A has a positive temperature coefficient of +0.083 %/°C, meaning its zener voltage increases by approximately 13.3 mV per °C rise from 25°C to 125°C. This drift must be accounted for in precision reference designs; however, the predictable linear behavior allows for compensation in feedback networks or calibration routines, especially in wide-temperature-range industrial systems.