Diodes Incorporated 1N5226B-T

Overview

1N5226B-T from Diodes Incorporated is a 3.3 V, ±5% tolerance, 500 mW glass-encapsulated Zener diode in DO-35 package, designed for precision voltage regulation and reference in low-power analog circuits, power supply feedback loops, and overvoltage protection. It delivers 20 mA test current, 28 Ω dynamic impedance at I_ZT, and -0.070 %/°C temperature coefficient.

For engineers reviewing the 1N5226B-T datasheet, 1N5226B-T pinout, 1N5226B-T application, or 1N5226B-T equivalent, key selection criteria include Zener voltage stability under thermal drift, low reverse leakage (25 µA @ 1.0 V), hermetic glass packaging for high-reliability environments, and compatibility with lead-free reflow processes per RoHS.

Technical Context

This discrete Zener diode operates in reverse breakdown mode to maintain stable DC voltage across its terminals. Its 3.3 V nominal Zener voltage is specified at 20 mA test current with ±5% tolerance, and exhibits a negative temperature coefficient (-0.070 %/°C) ensuring predictable drift behavior in temperature-varying circuits.

The device uses an epitaxial silicon structure housed in a hermetic DO-35 glass package with cathode band polarity marking. Thermal resistance is 300 °C/W (junction-to-ambient), requiring lead length control (≤9.5 mm) and ambient temperature derating above 75 °C to sustain rated 500 mW power dissipation.

Key Specifications

Pinout & Package

DO-35 glass axial package with cathode identified by a single black band. Leads are tin-silver solderable per MIL-STD-202, Method 208. Total weight ≈ 0.13 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMSZ5226B and 1N4728A, the 1N5226B-T offers legacy DO-35 compatibility and hermetic reliability but lacks SMT scalability or higher power headroom-making it best suited for repair, legacy board refresh, or niche high-stability analog references where glass encapsulation is prioritized.

Availability

1N5226B-T is available at Aetrix Electronics and suitable for voltage reference design, overvoltage protection, linear regulator feedback, and low-power bias generation requiring stable component supply and long-lifecycle support.

Supply support for 1N5226B-T 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, industry-standard components for power management, signal integrity, and protection.

The 1N52xxB series belongs to Diodes' legacy Zener diode product line, engineered for precision voltage regulation in cost-sensitive, thermally stable analog applications where hermetic glass packaging ensures long-term parameter consistency.

FAQ

What is the maximum continuous reverse voltage the 1N5226B-T can regulate?

The 1N5226B-T is rated for 3.3 V nominal Zener voltage with a guaranteed range of 3.14 V to 3.47 V at 20 mA test current. It is not designed for continuous operation above its specified Zener voltage - sustained reverse voltage beyond this range increases power dissipation and risks thermal failure unless current is strictly limited by external series resistance.

Can the 1N5226B-T be used in surface-mount assemblies?

No - the 1N5226B-T uses a DO-35 axial glass package with leads intended for through-hole mounting. For surface-mount equivalents, Diodes Incorporated recommends the MMSZ5226B in SOD-123 package, which shares identical electrical specifications but supports automated pick-and-place and reflow processes.

Why is the 1N5226B-T marked "Not Recommended for New Design"?

Diodes Incorporated designates the 1N5226B-T as "Not Recommended for New Design" because the MMSZ52xxB series offers identical electrical performance in a modern, surface-mount SOD-123 package with better manufacturability, smaller footprint, and equivalent reliability - making it the preferred choice for new PCB layouts and automated production.

How does the -0.070 %/°C temperature coefficient affect circuit performance?

A -0.070 %/°C temperature coefficient means the Zener voltage decreases by approximately 2.3 µV/°C (0.070% × 3.3 V) over temperature. In a 3.3 V reference, this results in ~1.5 mV drift across a 65°C range (−40°C to +25°C), which must be accounted for in high-accuracy analog systems or compensated via circuit design.