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

Vishay General Semiconductor - Diodes Division FESF8FT-E3/45

Name: FESF8FT-E3/45
Brand: Vishay General Semiconductor - Diodes Division
SKU: FESF8FT-E3/45
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FESF8FT-E3/45

Manufacturer:: Vishay General Semiconductor - Diodes Division

Category:: Single Diodes

Package:: TO-220-2 Full Pack, Isolated Tab

Datasheet:: FESF8FT-E3/45.pdf

Description:: DIODE GEN PURP 300V 8A ITO220AC

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Product details

Overview

FESF8FT-E3/45 from Vishay General Semiconductor is an ultrafast plastic rectifier diode in ITO-220AC package, rated for 300 V repetitive peak reverse voltage (V_RRM), 8.0 A average forward current (I_F(AV)), and 35 ns reverse recovery time (t_rr). It serves as a high-efficiency freewheeling or output rectifier in 50–100 kHz switching-mode power supplies.

For engineers reviewing the FESF8FT-E3/45 datasheet, FESF8FT-E3/45 pinout, FESF8FT-E3/45 application, or FESF8FT-E3/45 equivalent, key selection criteria include its 35 ns t_rr, 0.95 V forward voltage at 8 A, 125 A surge rating, TO-220 variant with insulated tab (ITO-220AC), and RoHS-compliant consumer-grade construction with JESD201 Class 1A whisker resistance.

Technical Context

This device belongs to Vishay's FES(F,B)8xT ultrafast rectifier family, optimized for high-frequency power conversion where low switching losses and fast recovery are critical. Its glass-passivated junction ensures stable performance under thermal cycling and high dv/dt stress.

The ITO-220AC package provides electrical isolation (1500 V_AC) between terminals and heatsink, enabling direct mounting to grounded heat sinks without insulating hardware-unlike standard TO-220AC. Thermal resistance from junction to case is 5.0 °C/W, supporting reliable operation up to 150 °C junction temperature.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	300 V - Maximum repetitive reverse blocking capability for use in 300 V DC bus or 210 V RMS AC input designs.
I_F(AV)	8.0 A at T_C = 100 °C - Sustained DC output current handling with appropriate heatsinking in SMPS secondary-side rectification.
t_rr	35 ns - Enables efficient operation in 50–100 kHz converters by minimizing reverse recovery charge and associated switching loss.
V_F	0.95 V at 8.0 A - Low conduction loss improves system efficiency and reduces thermal load on heatsink.
I_FSM	125 A (8.3 ms half-sine) - Withstands inrush and transient overloads common during power-up or fault conditions.
R_θJC	5.0 °C/W - Quantifies thermal path efficiency from die to case; used with heatsink R_θCA to calculate max ambient operating temperature.
Junction Temp	−55 °C to +150 °C - Supports industrial and extended-temperature applications including enclosed power supplies.

Pinout & Package

Package: ITO-220AC - Insulated tab variant of TO-220 with 1500 V_AC isolation between leads and heatsink mounting surface. Matte tin-plated leads, UL 94V-0 epoxy, JESD201 Class 1A whisker tested.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Anode)	Anode connection	Connected to switching node (e.g., transformer secondary center-tap or MOSFET drain) in bridge or freewheeling configuration.
Pin 2 (Cathode)	Cathode connection	Output rail connection; polarity-marked cathode band identifies this terminal for correct PCB layout and assembly.
Tab (Heatsink)	Electrically isolated case	Mounts directly to grounded chassis or heatsink without mica washer or insulator-reduces thermal interface resistance and assembly cost.

Key Features

Feature	Design Value
Glass passivated junction	Ensures long-term reliability under humidity, thermal stress, and high dv/dt without degradation of leakage or recovery behavior.
Ultrafast 35 ns t_rr	Reduces reverse recovery energy (E_rec) by >40% vs. standard fast recovery diodes, lowering MOSFET turn-on loss in synchronous rectified topologies.
1500 V_AC isolation (ITO-220AC)	Eliminates need for insulating hardware when mounted to conductive heatsinks-simplifies mechanical design and improves thermal performance.
RoHS-compliant & JESD201 Class 1A	Meets environmental compliance requirements and mitigates tin whisker risk in consumer-grade power supply applications.

Applications

AC-DC Adapter Output Rectification	DC-DC Converter Freewheeling Diode
Use Scenario: 12 V/5 A output stage of universal-input offline flyback adapter operating at 65 kHz. IC Role / Device Role / Timing Role: Output rectifier converting high-frequency transformer secondary AC to regulated DC, conducting during MOSFET off-time. Use Value: 35 ns t_rr minimizes voltage overshoot and EMI; 0.95 V V_F maintains >89% efficiency at full load without forced air cooling.	Use Scenario: Secondary-side freewheeling path in isolated 48 V to 12 V forward converter for telecom shelf power. IC Role / Device Role / Timing Role: Provides continuous current path for inductive energy storage during primary-side switch off-time; handles 8 A DC with 125 A surge margin. Use Value: 5.0 °C/W R_θJC enables compact heatsink design; ITO-220AC isolation allows direct mounting to 48 V return plane without creepage/clearance compromise.
Inverter DC Bus Clamping	Industrial UPS Battery Charging Stage
Use Scenario: Anti-parallel clamping diode across IGBTs in 3-phase 400 V AC motor drive inverter leg. IC Role / Device Role / Timing Role: Conducts reactive current during IGBT commutation; absorbs inductive kickback energy during switching transitions. Use Value: 125 A I_FSM withstands short-circuit transients; 300 V V_RRM matches 400 V DC bus with 33% safety margin per IEC 61800-5-1.	Use Scenario: Buck-derived battery charger for 24 V lead-acid bank in backup power system with 300 V DC input. IC Role / Device Role / Timing Role: Primary rectifier in high-side buck sync rectifier stage, operating continuously at 8 A average current. Use Value: −55 °C to +150 °C operating range supports unventilated cabinet deployment; RoHS compliance meets EU industrial equipment directives.

AC-DC Adapter Output Rectification

DC-DC Converter Freewheeling Diode

Use Scenario: 12 V/5 A output stage of universal-input offline flyback adapter operating at 65 kHz.

IC Role / Device Role / Timing Role: Output rectifier converting high-frequency transformer secondary AC to regulated DC, conducting during MOSFET off-time.

Use Value: 35 ns t_rr minimizes voltage overshoot and EMI; 0.95 V V_F maintains >89% efficiency at full load without forced air cooling.

Use Scenario: Secondary-side freewheeling path in isolated 48 V to 12 V forward converter for telecom shelf power.

IC Role / Device Role / Timing Role: Provides continuous current path for inductive energy storage during primary-side switch off-time; handles 8 A DC with 125 A surge margin.

Use Value: 5.0 °C/W R_θJC enables compact heatsink design; ITO-220AC isolation allows direct mounting to 48 V return plane without creepage/clearance compromise.

Inverter DC Bus Clamping

Industrial UPS Battery Charging Stage

Use Scenario: Anti-parallel clamping diode across IGBTs in 3-phase 400 V AC motor drive inverter leg.

IC Role / Device Role / Timing Role: Conducts reactive current during IGBT commutation; absorbs inductive kickback energy during switching transitions.

Use Value: 125 A I_FSM withstands short-circuit transients; 300 V V_RRM matches 400 V DC bus with 33% safety margin per IEC 61800-5-1.

Use Scenario: Buck-derived battery charger for 24 V lead-acid bank in backup power system with 300 V DC input.

IC Role / Device Role / Timing Role: Primary rectifier in high-side buck sync rectifier stage, operating continuously at 8 A average current.

Use Value: −55 °C to +150 °C operating range supports unventilated cabinet deployment; RoHS compliance meets EU industrial equipment directives.

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultrafast rectifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STTH8R03CW	TO-220AC (non-isolated), 300 V, 8 A, t_rr = 35 ns, V_F = 0.97 V - identical speed but requires insulator for grounded heatsink mounting.	Requires mica washer or silicone pad for heatsink isolation; unsuitable where space or thermal resistance constraints prohibit added interface layers.	Select when cost sensitivity outweighs thermal/mechanical integration benefits of ITO-220AC insulation.
ON Semiconductor MUR830E	TO-220AC, 300 V, 8 A, t_rr = 35 ns, V_F = 0.99 V - same speed and rating, but no isolation rating; JESD201 Class 2 (high-reliability grade).	Lacks 1500 V_AC isolation; intended for non-grounded heatsink or PCB-mounted thermal pads only.	Prefer for automotive or industrial designs requiring AEC-Q101 qualification and higher whisker resistance, provided isolation is handled externally.

Compared with STTH8R03CW and MUR830E, the FESF8FT-E3/45 uniquely combines 35 ns recovery, 0.95 V forward drop, and certified 1500 V_AC isolation in a single consumer-grade package-enabling simplified, lower-cost thermal management in grounded-chassis power supplies without sacrificing reliability or efficiency.

Availability

FESF8FT-E3/45 is available at Aetrix Electronics and suitable for AC-DC adapters, DC-DC converters, and industrial UPS systems requiring stable component supply, consistent parametric performance across production lots, and long-term lifecycle support.

Supply support for FESF8FT-E3/45 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

Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, MOSFETs, and optoelectronics with emphasis on reliability, efficiency, and application-specific optimization.

The FES(F,B)8xT series was engineered for high-frequency power conversion systems demanding low-loss, fast-switching rectification-particularly in space-constrained, thermally demanding offline and isolated DC-DC applications.

FAQ

What is the maximum junction temperature rating for the FESF8FT-E3/45?

The FESF8FT-E3/45 has a maximum junction temperature (T_J) of +150 °C, verified per Vishay Document Number 88600. This rating allows operation in high-ambient environments such as enclosed power supplies or industrial enclosures, provided thermal design maintains T_J ≤ 150 °C under worst-case load and ambient conditions. The FESF8FT-E3/45 must be derated above T_C = 100 °C per the published derating curve.

Does the FESF8FT-E3/45 have electrical isolation between the tab and leads?

Yes-the FESF8FT-E3/45 uses the ITO-220AC package, which provides 1500 V_AC isolation (1 minute test) between terminals and the heatsink tab. This is confirmed in the "MECHANICAL DATA" section of Vishay Document 88600. Unlike standard TO-220AC, the FESF8FT-E3/45 allows direct mounting to grounded metal surfaces without insulating hardware, reducing thermal resistance and assembly complexity.

What is the reverse recovery time (t_rr) of the FESF8FT-E3/45, and under what test conditions is it specified?

The FESF8FT-E3/45 has a maximum reverse recovery time (t_rr) of 35 ns, measured at I_F = 0.5 A, I_R = 1.0 A, and I_rr = 0.25 A, per the "ELECTRICAL CHARACTERISTICS" table in Vishay Document 88600. This value applies specifically to the FESF8FT variant (300 V rating) and is validated at T_C = 25 °C. The 35 ns t_rr enables efficient operation in 50–100 kHz switching applications.

Is the FESF8FT-E3/45 RoHS compliant and qualified for consumer applications?

Yes-the FESF8FT-E3/45 carries the "E3" suffix, indicating compliance with RoHS Directive 2002/95/EC and WEEE 2002/96/EC, and qualification to JESD201 Class 1A for tin whisker resistance. Vishay explicitly states this in the "FEATURES" section of Document 88600. The FESF8FT-E3/45 is designated for consumer-grade power supplies, not automotive or high-reliability applications requiring HE3 (AEC-Q101) grading.

How does the forward voltage (V_F) of the FESF8FT-E3/45 compare to other 300 V ultrafast rectifiers?

The FESF8FT-E3/45 specifies a maximum forward voltage (V_F) of 0.95 V at 8.0 A and T_C = 25 °C, among the lowest in its class. For comparison, STTH8R03CW specifies 0.97 V and ON Semiconductor MUR830E specifies 0.99 V under identical conditions. This 20–40 mV advantage directly reduces conduction loss and improves thermal performance in high-current, high-duty-cycle applications like DC-DC output stages.

FESF8FT-E3/45 Specifications

Product attributes: Attribute value

Manufacturer:: Vishay General Semiconductor - Diodes Division

Series:: -

Package/Case:: TO-220-2 Full Pack, Isolated Tab

Packaging:: Tube

Product Status:: Active

Technology:: Standard

Voltage - DC Reverse (Vr) (Max):: 300 V

Current - Average Rectified (Io):: 8A

Voltage - Forward (Vf) (Max) @ If:: 1.3 V @ 8 A

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

Reverse Recovery Time (trr):: 50 ns

Current - Reverse Leakage @ Vr:: 10 µA @ 300 V

Capacitance @ Vr, F:: -

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: ITO-220AC

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

FESF8FT-E3/45 FAQ

1.How can I place an order for FESF8FT-E3/45 through Aetrix?

Please submit a Request for Quotation (RFQ) for FESF8FT-E3/45 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 FESF8FT-E3/45 reliable?

The price and inventory of FESF8FT-E3/45 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FESF8FT-E3/45 is usually 5 days.

3.What payment methods are accepted for FESF8FT-E3/45?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FESF8FT-E3/45 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FESF8FT-E3/45?

FESF8FT-E3/45 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FESF8FT-E3/45 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 FESF8FT-E3/45?

For technical support, including FESF8FT-E3/45 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FESF8FT-E3/45 requirements.

6.How does Aetrix verify that FESF8FT-E3/45 is sourced from the original manufacturer or authorized distributors?

All FESF8FT-E3/45 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 FESF8FT-E3/45 meets industry standards.

7.What is the process for return or replacement of FESF8FT-E3/45?

All FESF8FT-E3/45 units undergo pre-shipment inspection (PSI). If there is an issue with FESF8FT-E3/45, 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 FESF8FT-E3/45 part is unused and in its original packaging.

Return procedure for FESF8FT-E3/45:

1.Submit a request within 90 days.

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

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