Taiwan Semiconductor Corporation HERAF805G

Overview

HERAF805G from Taiwan Semiconductor is an AEC-Q101-qualified, glass-passivated high-efficiency rectifier diode in ITO-220AC package, rated for 400 V repetitive peak reverse voltage (V_RRM), 8 A average forward current (I_F), and 1.3 V forward voltage at 8 A and 25°C. It delivers low reverse recovery time (50 ns) and 80 pF junction capacitance at 1 MHz and 4.0 V reverse bias, suited for freewheeling and DC–DC converter output stages.

For engineers reviewing the HERAF805G datasheet, HERAF805G pinout, HERAF805G application, or HERAF805G equivalent, key selection factors include its 400 V V_RRM, 150 A surge capability (I_FSM), 2 °C/W junction-to-case thermal resistance, AEC-Q101 qualification status, and ITO-220AC mechanical compatibility with heatsink mounting.

Technical Context

The HERAF805G is a single-die, ultra-fast recovery silicon rectifier optimized for switching-mode power supplies operating up to several hundred kHz. Its 50 ns reverse recovery time (t_rr) and low Q_rr minimize switching losses during turn-off transitions in flyback and forward converters.

Thermally, it features a low R_θJC of 2 °C/W and operates across –55°C to +150°C junction temperature range. The device uses glass passivation for stable surface leakage control and meets UL 94V-0 flammability and JESD201 Class 2 whisker resistance requirements.

Key Specifications

Pinout & Package

Package: ITO-220AC - 3-terminal through-hole package with isolated tab (cathode-connected), matte tin-plated leads, UL 94V-0 molding compound, and 0.56 N·m maximum mounting torque.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STTH8R04DJF and VS-8EWH04FN-M3, HERAF805G offers balanced trade-offs: mid-range V_F and t_rr, AEC-Q101 availability, and competitive thermal resistance-making it optimal for cost-sensitive automotive and industrial power supplies requiring proven reliability and supply continuity.

Availability

HERAF805G is available at Aetrix Electronics and suitable for DC–DC converter output rectification, switching mode inverter freewheeling, and industrial power supply input stage applications requiring stable component supply, long-term lifecycle support, and AEC-Q101-compliant alternatives.

Supply support for HERAF805G 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 HERAF series was developed to deliver high-reliability, ultra-fast recovery rectifiers with AEC-Q101 qualification, glass passivation, and industry-leading thermal performance for next-generation power conversion systems.

FAQ

What is the repetitive peak reverse voltage (V_RRM) rating for HERAF805G?

The HERAF805G has a repetitive peak reverse voltage (V_RRM) rating of 400 V, as confirmed in the Absolute Maximum Ratings table of the official Taiwan Semiconductor datasheet (Version K2105). This value is specific to HERAF805G and distinguishes it from adjacent family members such as HERAF804G (300 V) and HERAF806G (600 V). The 400 V rating defines its safe blocking capability in DC–DC and inverter applications.

Is HERAF805G AEC-Q101 qualified?

HERAF805G itself is not automatically AEC-Q101 qualified; qualification applies only to variants marked with the "H" suffix (e.g., HERAF805GH). The base HERAF805G ordering code denotes the standard industrial version. AEC-Q101 testing covers temperature cycling, humidity, and mechanical stress validation-critical for automotive under-hood deployment-and is explicitly noted in the Ordering Information section of the datasheet.

What is the forward voltage (V_F) of HERAF805G at 8 A and 25°C?

The forward voltage (V_F) of HERAF805G is specified as a maximum of 1.3 V at I_F = 8 A and T_J = 25°C, per the Electrical Specifications table. This value is measured under pulsed conditions (PW = 0.3 ms) to avoid self-heating effects. At elevated junction temperatures (e.g., 125°C), V_F decreases slightly due to semiconductor physics, but system-level thermal design must maintain case temperature within derating limits.

What is the junction capacitance (C_J) of HERAF805G and under what test conditions?

The junction capacitance (C_J) of HERAF805G is 80 pF, measured at 1 MHz with a 4.0 V reverse bias (V_R), as stated in the Electrical Specifications table. This parameter is critical for high-frequency snubber design and EMI filter modeling. The value applies specifically to HERAF805G and differs from HERAF806G–808G (60 pF), reflecting die geometry optimization across the voltage family.

What package type does HERAF805G use and how is the cathode connected?

HERAF805G uses the ITO-220AC package, a 3-terminal through-hole variant with an isolated metal tab. The cathode is electrically connected to both Lead 2 and the metal tab, as shown in the Marking Diagram and Package Outline. This configuration requires electrical isolation (e.g., mica washer or silicone pad) when mounting to a grounded heatsink-unless the circuit design intentionally references the cathode to chassis ground.