Taiwan Semiconductor Corporation 1N4728G

Overview

1N4728G from Taiwan Semiconductor is a 1 W, 3.3 V ±5% Zener diode in DO-41 glass package, designed for low-voltage stabilization and precision voltage reference in DC/DC converters, adapters, and lighting circuits. It features hermetically sealed construction, 100 °C/W junction-to-ambient thermal resistance, and 76 mA test current at nominal Zener voltage.

For engineers reviewing the 1N4728G datasheet, 1N4728G pinout, 1N4728G application, or 1N4728G equivalent, key selection criteria include Zener voltage tolerance (±5%), power dissipation (1 W), thermal performance (R_θJA = 100 °C/W), cathode-band polarity marking, and DO-41 mechanical compatibility with through-hole PCB layouts.

Technical Context

The 1N4728G operates as a single-die, silicon-based Zener diode optimized for stable reverse-biased breakdown at 3.3 V. Its electrical behavior is defined at 25 °C with I_ZT = 76 mA, Z_ZT = 10 Ω, and I_R ≤ 100 µA at V_R = 1 V.

It supports operation across -65 °C to +200 °C junction temperature range and uses pure tin-plated leads compliant with J-STD-002 solderability standards. The DO-41 package enables axial lead mounting with cathode band polarity identification and 242 mg unit weight.

Key Specifications

Pinout & Package

Package: DO-41 axial-leaded, hermetically sealed glass case with cathode band marking; dimensions per HQ2SD07-DO41-059 REV A; weight ≈ 242 mg.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4728A and BZX55C3V3, the 1N4728G offers superior thermal performance (100 °C/W) and full 1 W rating in the industry-standard DO-41 package-making it optimal for industrial adapters and DC/DC converters requiring robust, field-proven stabilization.

Availability

1N4728G is available at Aetrix Electronics and suitable for low-voltage stabilizers, adapter power supplies, and on-board DC/DC converters requiring stable component supply with RoHS compliance and DO-41 mechanical compatibility.

Supply support for 1N4728G 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

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving global industrial and consumer markets since 1992.

The 1N47xxG series was developed to deliver cost-effective, high-reliability Zener diodes with tight tolerances and hermetic packaging for power management and voltage reference applications in demanding environments.

FAQ

What is the nominal Zener voltage and tolerance of the 1N4728G?

The 1N4728G has a nominal Zener voltage of 3.3 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 3.135 V and 3.465 V when tested at I_ZT = 76 mA and T_A = 25 °C. This tolerance is confirmed in Taiwan Semiconductor's official datasheet revision G2301 and applies specifically to the 1N4728G variant-not the broader 1N47xx family.

What package type does the 1N4728G use, and how is polarity identified?

The 1N4728G uses the DO-41 axial-leaded glass package with cathode polarity indicated by a distinct color band on the body. The band marks the cathode terminal, which must be connected toward the higher-potential side in shunt regulator configurations. Mechanical dimensions conform to HQ2SD07-DO41-059 REV A, and leads are pure tin plated for J-STD-002 solderability.

What is the maximum power dissipation and thermal resistance of the 1N4728G?

The 1N4728G has a maximum power dissipation (P_D) of 1 W at 25 °C ambient, with a junction-to-ambient thermal resistance (R_θJA) of 100 °C/W. Its junction temperature can reach +200 °C, allowing reliable operation in high-temperature environments when properly heatsinked or mounted with adequate airflow.

How does the 1N4728G perform in terms of Zener impedance and leakage current?

The 1N4728G exhibits a Zener impedance (Z_ZT) of 10 Ω at I_ZT = 76 mA, ensuring stable regulation under load transients. Its leakage current is ≤100 µA at V_R = 1 V, confirming low off-state conduction-critical for battery-powered systems where quiescent current must be minimized.

Is the 1N4728G RoHS compliant and suitable for lead-free soldering?

Yes, the 1N4728G is RoHS compliant and features pure tin-plated leads qualified per J-STD-002 for both wave and reflow soldering. Its glass package and tin finish ensure compatibility with lead-free processes without compromising solder joint integrity or long-term reliability.