Taiwan Semiconductor Corporation HER305G

Overview

HER305G from Taiwan Semiconductor is a high-efficiency, ultra-fast recovery rectifier diode in DO-201AD package, rated for 400 V repetitive peak reverse voltage (VRRM), 3 A average forward current (IF), and 1.3 V forward voltage at 3 A and 25°C. It delivers 50 ns reverse recovery time (trr) and 60 pF junction capacitance at 1 MHz and 4.0 V reverse bias, suited for high-frequency switching power supplies.

For engineers reviewing the HER305G datasheet, HER305G pinout, HER305G application, or HER305G equivalent, key selection criteria include its 400 V VRRM rating, 50 ns trr performance, DO-201AD mechanical compatibility, low VF under load, and suitability for DC-DC converters requiring fast, efficient unidirectional conduction.

Technical Context

The HER305G employs a single-die silicon PN junction structure optimized for high-speed switching, with ultra-fast recovery enabled by controlled carrier lifetime reduction. Its thermal design supports 150°C maximum junction temperature and achieves 10°C/W junction-to-lead thermal resistance.

Electrical behavior is characterized by low conduction loss (VF = 1.3 V @ 3 A, 25°C) and minimal switching loss (trr = 50 ns, IF = 0.5 A, IR = 1.0 A, Irr = 0.25 A), making it suitable for operation in hard-switched topologies up to several hundred kHz.

Key Specifications

Pinout & Package

HER305G is housed in a DO-201AD axial-leaded package with cathode indicated by a band on the body. Leads are pure tin-plated and solderable per J-STD-002. Polarity is unambiguous: banded end = cathode; opposite end = anode.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-efficiency rectifier applications.

Compared with STTH3L04S and MUR3040CT, HER305G offers identical VRRM and IF ratings with competitive VF and trr, but in a compact, low-cost DO-201AD package ideal for cost-sensitive, space-constrained, single-output applications without heatsink requirements.

Availability

HER305G is available at Aetrix Electronics and suitable for DC-DC converters, switching mode inverters, and freewheeling applications requiring stable component supply, consistent parametric performance, and long-term industrial availability.

Supply support for HER305G 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, specializing in power rectifiers, TVS devices, and MOSFETs for industrial and automotive markets.

The HER301G–HER308G family was designed specifically for high-frequency, high-efficiency rectification in switching power supplies, emphasizing low VF, fast trr, and rugged DO-201AD packaging for reliability in harsh thermal and electrical environments.

FAQ

What is the maximum repetitive peak reverse voltage (VRRM) for HER305G?

The HER305G has a VRRM rating of 400 V, meaning it can reliably block reverse voltages up to this level without breakdown under repetitive conditions. This value is confirmed in the Absolute Maximum Ratings table of the official Taiwan Semiconductor datasheet (Version I2105) and defines the upper limit for input voltage in rectifier applications such as 36–48 V DC-DC front-ends or 230 VAC-derived supplies with sufficient derating margin. HER305G must not be operated beyond 400 V VRRM in any design.

What is the forward voltage drop of HER305G at 3 A and 25°C?

The forward voltage (VF) of HER305G is specified as a maximum of 1.3 V at 3 A forward current and 25°C junction temperature, per the Electrical Specifications table. This value reflects conduction loss under typical operating conditions and is measured using a 0.3 ms pulse test. At elevated temperatures (e.g., 125°C), VF decreases slightly due to semiconductor physics, but system-level thermal design must ensure junction temperature remains within the −55°C to +150°C range for reliable HER305G operation.

What is the reverse recovery time (trr) specification for HER305G?

The HER305G exhibits a reverse recovery time (trr) of 50 ns maximum, tested under conditions of IF = 0.5 A, IR = 1.0 A, and Irr = 0.25 A. This ultra-fast trr enables efficient use in high-frequency switching applications such as 200–500 kHz DC-DC converters, where slower diodes would incur excessive switching losses and EMI. The trr value is validated across production lots and is a key differentiator versus standard recovery rectifiers like 1N5408, which exceed 2000 ns.

Which package type does HER305G use, and what are its mechanical features?

HER305G uses the DO-201AD axial-leaded package, with dimensions and outline defined in Taiwan Semiconductor's Package Outline Dimensions drawing. Key mechanical features include UL 94V-0 compliant molding compound, pure tin-plated leads meeting J-STD-002 solderability, JESD201 Class 2 whisker resistance, and cathode polarity marked by a visible band. The package weighs approximately 1.10 g and supports manual or wave soldering without lead bending.

Is HER305G suitable for automotive applications?

Standard HER305G is not AEC-Q101 qualified; only variants marked with "H" suffix (e.g., HER305GH) meet AEC-Q101 stress testing requirements for automotive under-hood use. However, the base HER305G shares identical die and process technology, offering high reliability, 150°C TJ max, and robust surge capability (125 A IFSM), making it suitable for non-safety-critical industrial and commercial applications including automotive aftermarket power supplies where formal qualification is not mandated. Always verify compliance requirements before deployment.