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

Taiwan Semiconductor Corporation SF37G-A

Name: SF37G-A
Brand: Taiwan Semiconductor Corporation
SKU: SF37G-A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SF37G-A

Manufacturer:: Taiwan Semiconductor Corporation

Category:: Single Diodes

Package:: DO-201AD, Axial

Datasheet:: SF37G-A.pdf

Description:: 35NS, 3A, 500V, SUPER FAST RECOV

Quantity:: RFQ Add To RFQ list

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Inventory:3,369

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Product details

Overview

SF37G-A from Taiwan Semiconductor is a 3A, 500V super fast recovery rectifier diode in DO-201AD package, featuring 35ns reverse recovery time, 1.70V forward voltage at 3A/25°C, and 125A surge current capability; used in high-frequency switching mode power supplies and freewheeling paths.

For engineers reviewing the SF37G-A datasheet, SF37G-A pinout, SF37G-A application, or SF37G-A equivalent, key selection criteria include V_RRM = 500V, I_F = 3A, t_rr = 35ns, V_F = 1.70V, and thermal resistance R_θJL = 10°C/W - all critical for efficiency and reliability in DC-DC converters and inverters.

Technical Context

The SF37G-A is a single-die, silicon planar junction super fast rectifier optimized for high-frequency operation up to several hundred kHz. Its 35ns reverse recovery time and low junction capacitance (60pF at 4V) minimize switching losses and EMI generation in hard-switched topologies.

Designed for operation at junction temperatures up to +150°C, it supports continuous conduction mode (CCM) and discontinuous conduction mode (DCM) in boost, buck, and flyback converters. The DO-201AD package provides robust thermal performance with R_θJL = 10°C/W and R_θJA = 35°C/W under standard PCB mounting conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	500 V - maximum repetitive reverse voltage; defines safe blocking capability in 400V DC bus applications
I_F	3 A - average forward current; supports continuous output power up to ~15W at 5V with adequate heatsinking
t_rr	35 ns - reverse recovery time; enables efficient operation in 100–500 kHz SMPS without excessive switching loss
V_F	1.70 V @ 3A, 25°C - forward voltage drop; determines conduction loss of ~5.1W at full load, impacting thermal design
C_J	60 pF @ 4V - junction capacitance; limits high-frequency ringing and EMI in fast-edge switching circuits
I_FSM	125 A - non-repetitive surge current; withstands inrush and fault transients in industrial power supplies
R_θJL	10 °C/W - junction-to-lead thermal resistance; enables direct thermal path to PCB copper for passive cooling

Pinout & Package

DO-201AD axial-leaded package with cathode band marking; leads are pure tin plated, solderable per J-STD-002, and meet JESD 201 Class 1A whisker resistance.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry point	Connected to lower-potential side (e.g., switch node in buck converter); must handle full 3A RMS and 125A surge
Cathode	Forward current exit / reverse blocking terminal	Connected to higher-potential rail (e.g., output capacitor positive); marked by visible band; carries return current and blocks 500V reverse

Key Features

Feature	Design Value
Super fast recovery (t_rr = 35 ns)	Reduces turn-off switching loss and associated heat generation in high-frequency converters
Low forward voltage (V_F = 1.70 V)	Lowers conduction loss versus standard fast rectifiers (e.g., 1N5622), improving system efficiency at 3A load
High surge rating (I_FSM = 125 A)	Provides margin against line surges and startup inrush without derating or external protection
RoHS & halogen-free compliance	Meets IEC 61249-2-21 and environmental requirements for industrial and consumer end equipment
UL 94V-0 molding compound	Ensures flame-retardant housing integrity under fault conditions in enclosed power assemblies

Applications

DC-DC Converter Output Rectification	Switching Inverter Freewheeling
Use Scenario: Secondary-side rectification in isolated 48V-to-12V flyback or forward converters operating at 200–300 kHz. IC Role / Device Role / Timing Role: Unidirectional current valve converting high-frequency AC from transformer secondary into regulated DC output. Use Value: 35ns t_rr minimizes reverse recovery loss during each switching cycle, directly improving conversion efficiency by ~0.8% over standard fast diodes.	Use Scenario: Freewheeling path across IGBTs or MOSFETs in 3-phase motor drive inverters with 10–20 kHz PWM. IC Role / Device Role / Timing Role: Provides low-loss current recirculation path during active device off-time, preventing voltage spikes. Use Value: 125A I_FSM safely handles motor inductive kickback energy without snubber circuitry, reducing BOM count and layout area.
Buck Converter Synchronous Replacement	AC-DC Adapter Secondary Rectification
Use Scenario: Asynchronous buck regulator where synchronous FET replacement is impractical due to cost or control complexity. IC Role / Device Role / Timing Role: Standalone high-efficiency rectifier replacing Schottky diodes in 12V–24V input, 3.3V/5V output designs. Use Value: 500V V_RRM allows use with higher input rails (e.g., 48V PoE), while 1.70V V_F maintains competitive conduction loss vs. 45V Schottkys.	Use Scenario: Output rectification in compact 12V/24W wall adapters using quasi-resonant flyback topology. IC Role / Device Role / Timing Role: Primary output diode conducting during transformer demagnetization phase at ~65 kHz. Use Value: DO-201AD package enables manual or automated axial insertion; UL 94V-0 compound satisfies safety certification requirements for Class II enclosures.

DC-DC Converter Output Rectification

Switching Inverter Freewheeling

Use Scenario: Secondary-side rectification in isolated 48V-to-12V flyback or forward converters operating at 200–300 kHz.

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

Use Value: 35ns t_rr minimizes reverse recovery loss during each switching cycle, directly improving conversion efficiency by ~0.8% over standard fast diodes.

Use Scenario: Freewheeling path across IGBTs or MOSFETs in 3-phase motor drive inverters with 10–20 kHz PWM.

IC Role / Device Role / Timing Role: Provides low-loss current recirculation path during active device off-time, preventing voltage spikes.

Use Value: 125A I_FSM safely handles motor inductive kickback energy without snubber circuitry, reducing BOM count and layout area.

Buck Converter Synchronous Replacement

AC-DC Adapter Secondary Rectification

Use Scenario: Asynchronous buck regulator where synchronous FET replacement is impractical due to cost or control complexity.

IC Role / Device Role / Timing Role: Standalone high-efficiency rectifier replacing Schottky diodes in 12V–24V input, 3.3V/5V output designs.

Use Value: 500V V_RRM allows use with higher input rails (e.g., 48V PoE), while 1.70V V_F maintains competitive conduction loss vs. 45V Schottkys.

Use Scenario: Output rectification in compact 12V/24W wall adapters using quasi-resonant flyback topology.

IC Role / Device Role / Timing Role: Primary output diode conducting during transformer demagnetization phase at ~65 kHz.

Use Value: DO-201AD package enables manual or automated axial insertion; UL 94V-0 compound satisfies safety certification requirements for Class II enclosures.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STTH3L06S	V_RRM = 600V, t_rr = 30ns, V_F = 1.75V @ 3A, DO-201AD	Marginally faster recovery but higher V_F; slightly higher conduction loss at full load	Preferred when 600V blocking is required or when sub-30ns t_rr is critical for EMI reduction
ON Semi MUR3060CT	Dual common-cathode configuration, V_RRM = 600V, t_rr = 35ns, V_F = 1.75V @ 3A per diode, TO-220AC	Requires different footprint and thermal management; dual-diode structure suits bridge or dual-output designs	Selected when dual-diode integration or TO-220 thermal performance is needed, not for direct single-diode replacement

Compared with STTH3L06S and MUR3060CT, the SF37G-A offers optimal balance of 500V rating, 35ns recovery, and DO-201AD compatibility for cost-sensitive, space-constrained SMPS - avoiding over-specification while meeting core efficiency and reliability targets.

Availability

SF37G-A is available at Aetrix Electronics and suitable for DC-DC converters, switching inverters, and freewheeling applications requiring stable component supply, consistent parametric performance, and long-term industrial availability.

Supply support for SF37G-A 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 global industrial, computing, and power electronics markets since 1979.

The SF31G-A to SF38G-A series was developed specifically for high-frequency, high-reliability rectification in switching power supplies - emphasizing low t_rr, stable V_F, and robust surge handling in standard axial packages.

FAQ

What is the maximum repetitive peak reverse voltage (V_RRM) for SF37G-A?

The SF37G-A has a V_RRM of 500 V, confirmed in the Absolute Maximum Ratings table on page 2 of the official TSC datasheet (Version B2105). This rating ensures reliable blocking in 400V DC bus systems with sufficient safety margin. Exceeding this voltage risks avalanche breakdown and permanent damage to the SF37G-A.

What is the forward voltage (V_F) of SF37G-A at rated current?

The SF37G-A exhibits a typical forward voltage of 1.70 V at 3 A and 25°C, as specified in the Electrical Specifications table under "Forward voltage(1)" for SF37G-A/SF38G-A. This value increases with junction temperature and current - at 125°C, V_F rises to approximately 1.45 V due to negative temperature coefficient behavior.

Is SF37G-A RoHS and halogen-free compliant?

Yes, the SF37G-A is RoHS compliant and halogen-free per IEC 61249-2-21, as explicitly stated in the FEATURES section of the TSC datasheet. The molding compound meets UL 94V-0 flammability rating, and the pure tin-plated leads comply with J-STD-002 solderability standards - all verified for the SF37G-A ordering code.

What is the reverse recovery time (t_rr) of SF37G-A and how is it tested?

The SF37G-A has a maximum reverse recovery time of 35 ns, measured under conditions of I_F = 0.5 A, I_R = 1.0 A, and I_rr = 0.25 A, as defined in the Electrical Specifications table. This parameter is validated using the test circuit shown in Figure 6 of the datasheet and reflects performance at room temperature with controlled di/dt.

Which package does SF37G-A use and what are its mechanical features?

The SF37G-A uses the DO-201AD axial-leaded package, confirmed in the MECHANICAL DATA and ORDERING INFORMATION sections. It features pure tin-plated leads, UL 94V-0 molding compound, polarity indicated by cathode band, and weighs approximately 1.10 g. The package supports manual or automated through-hole assembly and meets JESD 201 Class 1A whisker resistance.

SF37G-A Specifications

Product attributes: Attribute value

Manufacturer:: Taiwan Semiconductor Corporation

Series:: -

Package/Case:: DO-201AD, Axial

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Standard

Voltage - DC Reverse (Vr) (Max):: 500 V

Current - Average Rectified (Io):: 3A

Voltage - Forward (Vf) (Max) @ If:: 1.7 V @ 3 A

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

Reverse Recovery Time (trr):: 35 ns

Current - Reverse Leakage @ Vr:: 5 µA @ 500 V

Capacitance @ Vr, F:: 60pF @ 4V, 1MHz

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-201AD

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

SF37G-A FAQ

1.How can I place an order for SF37G-A through Aetrix?

Please submit a Request for Quotation (RFQ) for SF37G-A 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 SF37G-A reliable?

The price and inventory of SF37G-A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SF37G-A is usually 5 days.

3.What payment methods are accepted for SF37G-A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SF37G-A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SF37G-A?

SF37G-A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SF37G-A 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 SF37G-A?

For technical support, including SF37G-A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SF37G-A requirements.

6.How does Aetrix verify that SF37G-A is sourced from the original manufacturer or authorized distributors?

All SF37G-A 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 SF37G-A meets industry standards.

7.What is the process for return or replacement of SF37G-A?

All SF37G-A units undergo pre-shipment inspection (PSI). If there is an issue with SF37G-A, 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 SF37G-A part is unused and in its original packaging.

Return procedure for SF37G-A:

1.Submit a request within 90 days.

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

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