Taiwan Semiconductor Corporation 1N4746G

Overview

1N4746G from Taiwan Semiconductor is a 1 W, 18 V ±5% Zener diode in DO-41 glass package, designed for precision voltage regulation and reference in low-power DC circuits; features 20 Ω zener impedance at 14 mA test current, 13.7 V minimum knee voltage, and operates up to +200 °C junction temperature.

For engineers reviewing the 1N4746G datasheet, 1N4746G pinout, 1N4746G application, or 1N4746G equivalent, this part serves as a stable, RoHS-compliant voltage clamp or reference in adapters, lighting drivers, and on-board DC/DC converters where tight tolerance and hermetic reliability are required.

Technical Context

The 1N4746G functions as a single-die, silicon planar Zener diode with sharp reverse breakdown at nominal 18 V. Its 20 Ω dynamic impedance (ZZT) at IZT = 14 mA ensures stable regulation under moderate load variation, while the 13.7 V minimum knee voltage (VR) defines usable clamping threshold before full conduction.

Thermal performance is defined by RθJA = 100 °C/W and RθJL = 53.5 °C/W, supporting operation across -65 °C to +200 °C junction range. The DO-41 hermetically sealed glass package enables reliable long-term stability in humid or thermally cycling environments.

Key Specifications

Pinout & Package

DO-41 axial-leaded glass package with cathode band marking; leads are pure tin plated and solderable per J-STD-002. No active pinout table - two-terminal device with anode and cathode terminals only.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4746A and BZX55C18, the 1N4746G offers full RoHS compliance, guaranteed 1 W dissipation, and lower dynamic impedance-making it preferred for new designs requiring regulatory alignment and robust voltage reference stability.

Availability

1N4746G is available at Aetrix Electronics and suitable for low-voltage stabilizers, LED lighting drivers, and AC/DC adapters requiring stable component supply, consistent Zener tolerance, and hermetic reliability in extended-temperature environments.

Supply support for 1N4746G 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 semiconductor manufacturer specializing in discrete power devices, rectifiers, and Zener diodes with global distribution and AEC-Q200 qualified lines.

The 1N47xxG series was developed to deliver high-reliability, RoHS-compliant Zener references for industrial power supplies and automotive auxiliary systems where long-term parametric stability and hermetic sealing are critical.

FAQ

What is the nominal Zener voltage and tolerance of the 1N4746G?

The 1N4746G has a nominal Zener voltage of 18 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 17.1 V and 18.9 V at 14 mA test current. This tolerance is confirmed in the Electrical Specifications table of the Taiwan Semiconductor datasheet (Version G2301), and applies across the full operating temperature range.

What is the maximum power dissipation rating for the 1N4746G?

The 1N4746G is rated for 1 W maximum continuous power dissipation at 25 °C ambient temperature. Derating is required above 25 °C per the thermal resistance specification (RθJA = 100 °C/W); for example, at 75 °C ambient, max power drops to 0.5 W to maintain TJ ≤ 200 °C.

What package type does the 1N4746G use, and how is polarity indicated?

The 1N4746G uses the DO-41 axial-leaded glass package. Polarity is indicated by a visible cathode band near one end of the glass body; the banded end is the cathode, and the unmarked end is the anode. Leads are pure tin plated and compliant with J-STD-002 solderability standards.

How does the 1N4746G compare to the 1N4746A variant?

The 1N4746G and 1N4746A share identical electrical parameters (18 V, ±5%, 1 W, 20 Ω ZZT), but the 1N4746G uses RoHS-compliant green compound and updated date coding (GYWWF format), whereas the 1N4746A lacks formal RoHS certification and uses legacy packaging. Both are DO-41, but only the 1N4746G meets current environmental compliance mandates.

What is the minimum knee voltage (VR) and leakage current specification for the 1N4746G?

The 1N4746G specifies a minimum knee voltage (VR) of 13.7 V at IZK = 0.25 mA, defining the onset of measurable Zener conduction. At VR = 13.7 V, leakage current (IR) is ≤5 µA - confirming low off-state current prior to regulation, critical for low-power standby circuits using the 1N4746G as a reference.