Microchip Technology 1N5263B

Overview

1N5263B from Microsemi is a 56 V, ±5% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 2.2 mA test current and 1300 Ω dynamic impedance at knee current, 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 1N5263B datasheet, 1N5263B pinout, 1N5263B application, or 1N5263B equivalent, key selection criteria include its 56 V nominal Zener voltage, ±5% tolerance (B suffix), 1300 Ω Zener impedance at IZK = 0.25 mA, temperature coefficient of +0.096 %/°C, and DO-35 mechanical compatibility with axial-leaded through-hole PCB layouts.

Technical Context

This discrete Zener diode operates in reverse breakdown mode with cathode band indicating the positive terminal during regulation. Its voltage regulation is stable across 0.25 mA to 20 mA operating current and maintains specified performance over –65°C to +175°C ambient range.

The device exhibits minimal junction capacitance (typical <2 pF at 0 V, per Figure 2), low forward voltage (≤1.5 V @ 200 mA), and inherent radiation hardness per MicroNote 050 - making it suitable for aerospace, industrial, and high-reliability embedded systems where ESD insensitivity and thermal robustness are required.

Key Specifications

Pinout & Package

DO-35 (DO-204AH) glass axial-leaded package: hermetically sealed, tin-lead or RoHS-compliant matte-tin plating, cathode indicated by colored band, weight 0.2 g, lead length ≥10 mm for thermal rating compliance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5263B, the BZX55-C56 offers identical Zener voltage, tolerance, impedance, and DO-35 packaging - enabling seamless second-source qualification - while the 1N4744A serves distinct low-voltage, high-power use cases and requires PCB redesign due to DO-41 size and thermal profile differences.

Availability

1N5263B is available at Aetrix Electronics and suitable for industrial power monitoring, aerospace voltage reference, and automotive engine control applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for 1N5263B 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 1N52xxB series was designed specifically for precision voltage regulation in mission-critical systems where wide temperature operation, ESD immunity, and JEDEC-standard interchangeability are mandatory design requirements.

FAQ

What is the nominal Zener voltage and tolerance of the 1N5263B?

The 1N5263B has a nominal Zener voltage of 56 V with a tolerance of ±5%, as indicated by the "B" suffix per JEDEC standard. This tolerance is guaranteed over the full operating temperature range of –65°C to +175°C and verified at 2.2 mA test current. The 1N5263B's voltage stability makes it suitable for applications requiring predictable regulation margins without active trimming.

What package type and mounting configuration does the 1N5263B use?

The 1N5263B uses a DO-35 (DO-204AH) glass axial-leaded package with hermetically sealed construction and tin-lead or RoHS-compliant matte-tin plating. The cathode is marked by a colored band, and the device must be mounted with the banded end positive relative to the anode for Zener operation. Lead length must be ≥10 mm from the body to meet thermal resistance specifications.

How does the temperature coefficient affect the 1N5263B's performance in varying thermal environments?

With a temperature coefficient of +0.096 %/°C, the 1N5263B's Zener voltage increases by approximately 53.8 mV per °C rise above 25°C. This predictable drift allows designers to compensate in high-accuracy references or accept bounded error in less sensitive applications. The coefficient is measured between 25°C and 125°C at rated IZT, ensuring consistency in extended-temperature deployments.

Can the 1N5263B be used in radiation-exposed environments such as space or nuclear instrumentation?

Yes, the 1N5263B is inherently radiation hard per MicroNote 050, making it suitable for low-dose-rate space applications and nuclear instrumentation where total ionizing dose (TID) resilience is required. Its glass package and process design provide demonstrated tolerance without additional shielding, and the 1N5263B has been qualified for use in JANTXV and JANS screening levels when ordered with appropriate prefixes.

What is the maximum reverse current specification for the 1N5263B at its rated Zener voltage?

The 1N5263B specifies a maximum reverse current (IR) of 0.1 μA at VR = 45 V, which is 80% of its nominal 56 V Zener voltage. This ultra-low leakage ensures minimal power loss in high-impedance bias networks and preserves accuracy in precision reference designs where load current must remain strictly defined by external circuitry.