Taiwan Semiconductor Corporation 1N4745G

Overview

1N4745G from Taiwan Semiconductor is a 1 W, 16 V ±5% Zener diode in DO-41 glass package, designed for precision voltage regulation and reference applications with 15.5 mA test current, 16 Ω dynamic impedance at I_ZT, and 12.2 V minimum knee voltage. It operates across –65°C to +200°C junction temperature range and serves in DC/DC converter feedback loops and low-voltage stabilizers.

For engineers reviewing the 1N4745G datasheet, 1N4745G pinout, 1N4745G application, or 1N4745G equivalent, key selection criteria include Zener voltage tolerance (±5%), thermal resistance (R_θJA = 100°C/W), cathode-band polarity marking, DO-41 mechanical compatibility, and leakage current ≤5 µA at 12.2 V reverse bias.

Technical Context

The 1N4745G functions as a single-die, silicon-based Zener diode operating in reverse breakdown mode. Its 16 V nominal Zener voltage is specified at 15.5 mA test current (I_ZT) with dynamic impedance of 16 Ω, and it maintains stable regulation down to 0.25 mA knee current (I_ZK) where V_Z drops to 12.2 V.

Thermally, it features R_θJL = 53.5°C/W and R_θJA = 100°C/W, enabling reliable operation up to +200°C junction temperature. The hermetically sealed DO-41 glass package ensures long-term stability and RoHS compliance without silicone encapsulation.

Key Specifications

Pinout & Package

Package: DO-41 glass axial lead package with cathode band marking; pure tin-plated leads compliant with J-STD-002 solderability; weight ≈242 mg.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4745A and BZX55C16, the 1N4745G offers superior thermal performance (R_θJA = 100°C/W) and full 1 W dissipation in the industry-standard DO-41 package-making it optimal for higher-power stabilization where reliability across wide temperature ranges is critical.

Availability

1N4745G is available at Aetrix Electronics and suitable for low-voltage stabilizers, on-board DC/DC converters, and adapter designs requiring stable component supply, consistent Zener voltage tolerance, and proven DO-41 mechanical reliability.

Supply support for 1N4745G 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 industrial, computing, and consumer markets since 1979.

The 1N47xxG series was developed to deliver high-reliability, glass-encapsulated Zener diodes with tight voltage tolerances and extended temperature capability for mission-critical voltage reference and protection roles.

FAQ

What is the Zener voltage tolerance of the 1N4745G?

The 1N4745G has a nominal Zener voltage of 16 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 15.2 V and 16.8 V when tested at I_ZT = 15.5 mA. 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 1N4745G?

The 1N4745G is rated for 1 W maximum power dissipation at 25°C ambient temperature. Derating is linear above 25°C at 10 mW/°C, reaching zero dissipation at +125°C ambient-based on R_θJA = 100°C/W. This rating assumes adequate PCB copper area for heat spreading per DO-41 mounting guidelines.

How is polarity indicated on the 1N4745G package?

Polarity on the 1N4745G is marked by a distinct cathode band-a black annular ring located near one end of the DO-41 glass body. The terminal adjacent to this band is the cathode; the opposite lead is the anode. This marking aligns with JEDEC DO-41 standards and is visible before and after soldering.

What is the leakage current specification for the 1N4745G?

The 1N4745G specifies a maximum leakage current (I_R) of 5 µA when reverse-biased at 12.2 V (V_R = V_ZK). This value is measured at 25°C and reflects the device's ability to maintain low standby current in high-impedance reference networks-critical for battery-operated systems.

Is the 1N4745G RoHS compliant?

Yes, the 1N4745G is RoHS compliant, as explicitly stated in the Features section of the Taiwan Semiconductor datasheet (Version G2301). It contains no lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), or polybrominated diphenyl ethers (PBDE), and uses green compound encapsulation per marking diagram.