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Home > Products > Discrete Semiconductor Products > Diodes > Rectifiers > Single Diodes

Taiwan Semiconductor Corporation HER205G

Name: HER205G
Brand: Taiwan Semiconductor Corporation
SKU: HER205G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: HER205G

Manufacturer:: Taiwan Semiconductor Corporation

Category:: Single Diodes

Package:: DO-204AC, DO-15, Axial

Datasheet:: HER205G.pdf

Description:: DIODE GEN PURP 400V 2A DO204AC

Quantity:: RFQ Add To RFQ list

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Inventory:3,289

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Product details

Overview

HER205G from Taiwan Semiconductor is a high-efficiency, glass-passivated silicon rectifier diode rated for 400 V repetitive peak reverse voltage (V_RRM), 2 A average forward current (I_F), and 60 A surge current (I_FSM), with 1.3 V forward voltage at 2 A and 25°C. It serves as a fast-recovery freewheeling or output rectifier in switching-mode power supplies.

For engineers reviewing the HER205G datasheet, HER205G pinout, HER205G application, or HER205G equivalent, key selection factors include its 50 ns reverse recovery time (t_rr), 35 pF junction capacitance at 1 MHz and 4.0 V reverse bias, DO-204AC (DO-15) package, AEC-Q101 qualification option, and thermal resistance of 60°C/W.

Technical Context

The HER205G implements a single-die, planar passivated junction structure optimized for high-speed switching and low conduction loss. Its 50 ns reverse recovery time enables use in 100–500 kHz SMPS topologies without excessive switching loss or EMI generation.

It operates across –55°C to +150°C junction temperature range, with 150°C maximum rating and 60°C/W junction-to-ambient thermal resistance. The device uses pure tin-plated leads compliant with J-STD-002 and meets JESD 201 Class 2 whisker resistance.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	400 V - Maximum non-repetitive reverse voltage the diode blocks reliably in circuit
I_F	2 A - Continuous average forward current capability at 75°C ambient with adequate heatsinking
t_rr	50 ns - Reverse recovery time under I_F = 0.5 A, I_R = 1.0 A, I_rr = 0.25 A; critical for minimizing switching loss in high-frequency converters
V_F	1.3 V @ 2 A, 25°C - Forward voltage drop determining conduction loss and thermal load at rated current
C_J	35 pF @ 1 MHz, V_R = 4.0 V - Junction capacitance affecting high-frequency noise coupling and snubber design
R_θJA	60 °C/W - Thermal resistance from junction to ambient; defines required PCB copper area or heatsink for thermal management

Pinout & Package

HER205G is housed in a DO-204AC (DO-15) axial-leaded package with cathode indicated by a band. Leads are pure tin-plated and solderable per J-STD-002.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry point	Connected to lower-potential side (e.g., switch node or ground return) in freewheeling path
Cathode	Forward current exit point	Connected to higher-potential rail (e.g., output capacitor positive or DC bus); marked with band

Key Features

Feature	Design Value
High-efficiency rectification	1.3 V V_F at 2 A reduces conduction loss vs. standard PN diodes (e.g., 1N4007: ~1.7 V)
Fast reverse recovery	50 ns t_rr supports operation up to ~500 kHz without excessive switching loss or ringing
Glass passivated junction	Enhances moisture resistance and long-term reliability in humid or industrial environments
AEC-Q101 qualification option	HER205GH variant available for automotive-grade power supply designs requiring stress-tested components

Applications

DC–DC Converter Output Rectification	Switching Mode Inverter Freewheeling
Use Scenario: Secondary-side rectification in isolated flyback or forward converters delivering 12–48 V outputs at up to 2 A. IC Role / Device Role / Timing Role: Unidirectional current valve converting high-frequency AC from transformer secondary into regulated DC output. Use Value: 1.3 V V_F and 50 ns t_rr minimize total power loss and improve efficiency over 85% at full load.	Use Scenario: Freewheeling path across inductive loads (e.g., motor windings or relay coils) in half-bridge inverters operating at 20–100 kHz. IC Role / Device Role / Timing Role: Provides low-loss current recirculation path during switch off-time to clamp inductive kickback. Use Value: 60 A I_FSM withstands transient surges; 35 pF C_J limits capacitive coupling noise into gate drive circuits.
AC–DC Adapter Secondary Rectifier	Industrial Power Supply Snubber Diode
Use Scenario: Output rectification in compact 24 W–60 W wall adapters using quasi-resonant flyback controllers. IC Role / Device Role / Timing Role: High-reliability rectifier handling continuous 2 A load with minimal thermal rise on FR-4 PCB. Use Value: DO-204AC package fits standard through-hole footprints; 60°C/W R_θJA allows natural convection cooling without heatsink.	Use Scenario: RC snubber network diode in 3 kW industrial UPS inverters to absorb turn-off energy from IGBTs. IC Role / Device Role / Timing Role: Fast clamping element that conducts only during brief voltage overshoot events. Use Value: 50 ns t_rr ensures rapid turn-on before voltage spike peaks; 400 V V_RRM provides margin above 340 V DC bus.

DC–DC Converter Output Rectification

Switching Mode Inverter Freewheeling

Use Scenario: Secondary-side rectification in isolated flyback or forward converters delivering 12–48 V outputs at up to 2 A.

IC Role / Device Role / Timing Role: Unidirectional current valve converting high-frequency AC from transformer secondary into regulated DC output.

Use Value: 1.3 V V_F and 50 ns t_rr minimize total power loss and improve efficiency over 85% at full load.

Use Scenario: Freewheeling path across inductive loads (e.g., motor windings or relay coils) in half-bridge inverters operating at 20–100 kHz.

IC Role / Device Role / Timing Role: Provides low-loss current recirculation path during switch off-time to clamp inductive kickback.

Use Value: 60 A I_FSM withstands transient surges; 35 pF C_J limits capacitive coupling noise into gate drive circuits.

AC–DC Adapter Secondary Rectifier

Industrial Power Supply Snubber Diode

Use Scenario: Output rectification in compact 24 W–60 W wall adapters using quasi-resonant flyback controllers.

IC Role / Device Role / Timing Role: High-reliability rectifier handling continuous 2 A load with minimal thermal rise on FR-4 PCB.

Use Value: DO-204AC package fits standard through-hole footprints; 60°C/W R_θJA allows natural convection cooling without heatsink.

Use Scenario: RC snubber network diode in 3 kW industrial UPS inverters to absorb turn-off energy from IGBTs.

IC Role / Device Role / Timing Role: Fast clamping element that conducts only during brief voltage overshoot events.

Use Value: 50 ns t_rr ensures rapid turn-on before voltage spike peaks; 400 V V_RRM provides margin above 340 V DC bus.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STTH2R04	400 V V_RRM, 2 A I_F, 1.35 V V_F, 55 ns t_rr, TO-220AC package	Larger footprint, higher thermal mass; requires mounting screw or heatsink	Select when higher surge robustness or forced-air cooling is needed
ES2D	200 V V_RRM, 2 A I_F, 0.95 V V_F, 35 ns t_rr, DO-214AA (SMA) package	Lower voltage rating; surface-mount; faster recovery but insufficient for 400 V bus	Select only for ≤200 V applications where space and speed outweigh voltage margin

Compared with STTH2R04 and ES2D, the HER205G offers optimal balance of 400 V rating, axial DO-204AC fit, 50 ns recovery, and cost-effective through-hole assembly-making it preferred for mid-power industrial adapters and inverters where board-level reliability and legacy footprint compatibility matter.

Availability

HER205G 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 manufacturing continuity.

Supply support for HER205G 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 devices, rectifiers, TVS diodes, and MOSFETs.

The HER20xG series was designed specifically for high-efficiency, high-reliability AC–DC and DC–DC power conversion in industrial, computing, and automotive auxiliary systems-emphasizing low V_F, fast t_rr, and robust thermal performance in standard axial packages.

FAQ

What is the maximum repetitive peak reverse voltage (V_RRM) for HER205G?

The HER205G has a V_RRM of 400 V, meaning it reliably blocks up to 400 V of reverse voltage in repetitive operation. This rating is confirmed in the Absolute Maximum Ratings table of the official Taiwan Semiconductor datasheet (Version G2105) and applies across the full operating temperature range. Exceeding this voltage risks avalanche breakdown or permanent damage to the HER205G.

What is the forward voltage (V_F) of HER205G at rated current?

The HER205G exhibits a typical forward voltage of 1.3 V at 2 A and 25°C, as specified in the Electrical Specifications table. This value increases with junction temperature and current-e.g., ~1.45 V at 125°C. The 1.3 V V_F directly determines conduction loss (P_cond = V_F × I_F) and must be factored into thermal design for the HER205G.

Does HER205G have AEC-Q101 qualification?

The base HER205G is not AEC-Q101 qualified; however, the HER205GH variant-identical electrically and mechanically but with additional automotive-grade stress testing-is qualified per AEC-Q101. The "H" suffix denotes qualification, and both HER205G and HER205GH share the same DO-204AC package and electrical specs. Always verify the full ordering code when selecting for automotive applications.

What is the junction capacitance (C_J) of HER205G and how is it measured?

The HER205G has a junction capacitance of 35 pF, measured at 1 MHz with 4.0 V reverse bias (V_R), per the Electrical Specifications table. This value is critical for high-frequency snubber and EMI filter design. C_J decreases as reverse voltage increases-e.g., ~25 pF at 10 V-and must be modeled dynamically in SPICE simulations of the HER205G.

What package type does HER205G use and what are its mechanical features?

The HER205G uses the DO-204AC (DO-15) axial-leaded package, with pure tin-plated leads compliant with J-STD-002 solderability and JESD 201 Class 2 whisker resistance. The case is UL 94V-0 rated molding compound; polarity is marked by a cathode band. Its 0.400 g weight and standardized lead spacing make the HER205G compatible with automated through-hole insertion and wave soldering processes.

HER205G Specifications

Product attributes: Attribute value

Manufacturer:: Taiwan Semiconductor Corporation

Series:: -

Package/Case:: DO-204AC, DO-15, Axial

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Standard

Voltage - DC Reverse (Vr) (Max):: 400 V

Current - Average Rectified (Io):: 2A

Voltage - Forward (Vf) (Max) @ If:: 1.3 V @ 2 A

Speed:: Fast Recovery =< 500ns, > 200mA (Io)

Reverse Recovery Time (trr):: 50 ns

Current - Reverse Leakage @ Vr:: 5 µA @ 400 V

Capacitance @ Vr, F:: 35pF @ 4V, 1MHz

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-204AC (DO-15)

Operating Temperature - Junction:: -55°C ~ 150°C

HER205G FAQ

1.How can I place an order for HER205G through Aetrix?

Please submit a Request for Quotation (RFQ) for HER205G on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for HER205G reliable?

The price and inventory of HER205G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for HER205G is usually 5 days.

3.What payment methods are accepted for HER205G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for HER205G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for HER205G?

HER205G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your HER205G order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for HER205G?

For technical support, including HER205G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your HER205G requirements.

6.How does Aetrix verify that HER205G is sourced from the original manufacturer or authorized distributors?

All HER205G products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that HER205G meets industry standards.

7.What is the process for return or replacement of HER205G?

All HER205G units undergo pre-shipment inspection (PSI). If there is an issue with HER205G, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The HER205G part is unused and in its original packaging.

Return procedure for HER205G:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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