Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

Taiwan Semiconductor Corporation SF12G-K

Name: SF12G-K
Brand: Taiwan Semiconductor Corporation
SKU: SF12G-K
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: SF12G-K

Manufacturer:: Taiwan Semiconductor Corporation

Category:: Single Diodes

Package:: DO-204AL, DO-41, Axial

Datasheet:: SF12G-K.pdf

Description:: 35NS, 1A, 100V, SUPER FAST RECOV

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:3,577

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

SF12G-K from Taiwan Semiconductor is a 1A, 100V super fast rectifier diode in DO-204AL (DO-41) package, featuring 35ns reverse recovery time, 0.95V forward voltage at 1A/25°C, and 30A surge current capability. It serves as a freewheeling or output rectifier in DC-DC converters and switching-mode inverters requiring high efficiency and low conduction loss.

For engineers reviewing the SF12G-K datasheet, SF12G-K pinout, SF12G-K application, or SF12G-K equivalent, key selection criteria include V_RRM = 100 V, I_F = 1 A, t_rr = 35 ns, V_F = 0.95 V, and thermal resistance R_θJL = 20 °C/W - all critical for high-frequency power conversion designs with thermal constraints.

Technical Context

This super fast rectifier uses a single-die silicon PN junction optimized for reduced minority-carrier lifetime, enabling rapid turn-off and minimal reverse recovery charge. Its 35 ns t_rr and low 20 pF junction capacitance support operation up to several hundred kHz in hard-switched topologies.

The device operates across –55°C to +150°C junction temperature range, with 80 °C/W junction-to-ambient thermal resistance and 20 °C/W junction-to-lead resistance - indicating effective heat transfer to PCB copper or heatsinking leads in compact layouts.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	100 V - maximum repetitive reverse voltage; defines safe blocking capability in 12–48 V output DC-DC stages
I_F	1 A continuous - average forward current rating at T_A = 75°C; sets baseline conduction capacity
t_rr	35 ns - measured at I_F = 0.5 A, I_R = 1.0 A, I_rr = 0.25 A; enables efficient operation in 200–500 kHz SMPS
V_F	0.95 V @ 1 A, 25°C - low forward drop reduces conduction loss and improves system efficiency
R_θJL	20 °C/W - junction-to-lead thermal resistance; supports direct lead soldering to copper pour for thermal management
C_J	20 pF @ 1 MHz, 4 V - low junction capacitance minimizes switching noise and EMI in high-dv/dt circuits

Pinout & Package

Package: DO-204AL (DO-41), axial lead, epoxy-molded case with cathode band marking. RoHS-compliant, halogen-free, UL 94V-0 rated molding compound. Pure tin-plated leads, J-STD-002 solderable.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry point	Connected to lower-potential node (e.g., switch node in buck converter); requires adequate trace width for 1 A RMS
Cathode	Forward current exit / reverse blocking terminal	Marked by band; ties to output rail or ground return; carries full load current and absorbs reverse recovery energy

Key Features

Feature	Design Value
Super fast recovery	t_rr = 35 ns ensures minimal switching loss and reduced EMI in high-frequency DC-DC converters
Low forward voltage	V_F = 0.95 V @ 1 A directly lowers conduction loss versus standard rectifiers (e.g., 1N4007: ~1.1 V)
High surge robustness	I_FSM = 30 A (8.3 ms half-sine) withstands startup surges and transient overloads without failure
Thermally optimized package	R_θJL = 20 °C/W enables reliable operation at 1 A with minimal heatsinking on standard FR-4 PCB

Applications

Buck Converter Output Rectification	Freewheeling Diode in Motor Drives
Use Scenario: Used as the low-side synchronous rectifier replacement in non-isolated 12 V input / 3.3–5 V output buck converters. IC Role / Device Role / Timing Role: Freewheeling path during high-side switch off-time; conducts 1 A average current with 35 ns turn-off to minimize dead-time losses. Use Value: 0.95 V V_F reduces conduction loss by ~15% vs. 1N5819 (0.45 V Schottky limited to 40 V), while 100 V V_RRM supports wider input ranges.	Use Scenario: Placed across brushed DC motor terminals or H-bridge leg to clamp inductive kickback. IC Role / Device Role / Timing Role: Clamping diode absorbing stored inductive energy; must recover before next PWM edge to prevent shoot-through. Use Value: 35 ns t_rr prevents reverse conduction overlap in 20–100 kHz PWM drives, avoiding MOSFET cross-conduction and thermal runaway.
AC-DC Adapter Secondary Rectifier	Industrial SMPS Input Stage Clamp
Use Scenario: Output rectifier in 24 V, 1 A offline flyback adapter with universal AC input. IC Role / Device Role / Timing Role: Converts transformer secondary AC to regulated DC; handles 1 A continuous and 30 A surge during cold start. Use Value: 100 V V_RRM provides margin above reflected 85 V peak (for 264 VAC input), while 0.95 V V_F maintains >85% efficiency at full load.	Use Scenario: Snubber or clamp diode in 48 V industrial DC bus converters handling regenerative braking energy. IC Role / Device Role / Timing Role: Absorbs voltage spikes from leakage inductance during switch turn-off; recovers rapidly to reset before next cycle. Use Value: 20 pF C_J and 35 ns t_rr reduce snubber loss and improve clamp response versus slower 1N4937 (200 ns).

Buck Converter Output Rectification

Freewheeling Diode in Motor Drives

Use Scenario: Used as the low-side synchronous rectifier replacement in non-isolated 12 V input / 3.3–5 V output buck converters.

IC Role / Device Role / Timing Role: Freewheeling path during high-side switch off-time; conducts 1 A average current with 35 ns turn-off to minimize dead-time losses.

Use Value: 0.95 V V_F reduces conduction loss by ~15% vs. 1N5819 (0.45 V Schottky limited to 40 V), while 100 V V_RRM supports wider input ranges.

Use Scenario: Placed across brushed DC motor terminals or H-bridge leg to clamp inductive kickback.

IC Role / Device Role / Timing Role: Clamping diode absorbing stored inductive energy; must recover before next PWM edge to prevent shoot-through.

Use Value: 35 ns t_rr prevents reverse conduction overlap in 20–100 kHz PWM drives, avoiding MOSFET cross-conduction and thermal runaway.

AC-DC Adapter Secondary Rectifier

Industrial SMPS Input Stage Clamp

Use Scenario: Output rectifier in 24 V, 1 A offline flyback adapter with universal AC input.

IC Role / Device Role / Timing Role: Converts transformer secondary AC to regulated DC; handles 1 A continuous and 30 A surge during cold start.

Use Value: 100 V V_RRM provides margin above reflected 85 V peak (for 264 VAC input), while 0.95 V V_F maintains >85% efficiency at full load.

Use Scenario: Snubber or clamp diode in 48 V industrial DC bus converters handling regenerative braking energy.

IC Role / Device Role / Timing Role: Absorbs voltage spikes from leakage inductance during switch turn-off; recovers rapidly to reset before next cycle.

Use Value: 20 pF C_J and 35 ns t_rr reduce snubber loss and improve clamp response versus slower 1N4937 (200 ns).

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STTH1R04	V_RRM = 400 V, t_rr = 30 ns, V_F = 1.15 V @ 1 A - higher blocking, faster recovery, but higher VF	Preferred where >100 V blocking or <35 ns t_rr required; less optimal for low-VF priority designs	Select STTH1R04 only if system requires ≥400 V V_RRM; otherwise SF12G-K offers better efficiency at 100 V class
ON Semi MUR105	V_RRM = 50 V, t_rr = 50 ns, V_F = 0.92 V @ 1 A - lower V_RRM, slower recovery, slightly lower VF	Suitable for ≤50 V systems (e.g., USB PD 20 V rails); not rated for 100 V blocking	Choose MUR105 only for 50 V or lower applications; SF12G-K is mandatory for 100 V-rated designs

Compared with STTH1R04 and MUR105, the SF12G-K uniquely balances 100 V blocking, 35 ns speed, and 0.95 V forward drop - making it the most thermally efficient choice for 24–48 V industrial DC-DC outputs where voltage margin and switching loss are both constrained.

Availability

SF12G-K 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 RoHS/halogen-free compliance.

Supply support for SF12G-K 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 diodes, and MOSFETs since 1979.

The SF1xG-K series was developed specifically for high-efficiency, high-reliability power conversion in industrial and telecom infrastructure - emphasizing low V_F, fast t_rr, and robust surge handling in standardized DO-41 packaging.

FAQ

What is the maximum repetitive peak reverse voltage (V_RRM) for SF12G-K?

The SF12G-K has a V_RRM of 100 V, as confirmed in the Absolute Maximum Ratings table of the official Taiwan Semiconductor datasheet (Version B2104). This rating allows safe operation in 24 V and 48 V DC-DC output stages with sufficient margin against transient spikes. Exceeding 100 V risks avalanche breakdown and permanent damage to the SF12G-K junction.

What is the forward voltage (V_F) of SF12G-K at rated current?

The SF12G-K exhibits a typical forward voltage of 0.95 V at 1 A and 25°C, per the Electrical Specifications table. This value increases with junction temperature and current - e.g., ~1.05 V at 1 A and 100°C. The low V_F directly reduces conduction loss compared to general-purpose rectifiers like 1N4007, improving overall system efficiency in the SF12G-K's target applications.

Does SF12G-K have a specified reverse recovery time (t_rr)?

Yes, the SF12G-K 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. This parameter is explicitly listed in the Electrical Specifications section of the Taiwan Semiconductor datasheet and confirms its classification as a super fast rectifier - critical for minimizing switching loss in high-frequency SMPS using the SF12G-K.

What package type does SF12G-K use, and is it RoHS compliant?

The SF12G-K uses the DO-204AL (DO-41) axial-leaded package with cathode band marking, pure tin-plated leads, and UL 94V-0 rated epoxy. It is RoHS compliant and halogen-free per IEC 61249-2-21, as stated in the Features and Mechanical Data sections. This makes the SF12G-K suitable for environmentally regulated industrial and telecom equipment where lead-free assembly and material compliance are mandatory.

What is the surge current rating (I_FSM) of SF12G-K, and how is it tested?

The SF12G-K has a peak non-repetitive forward surge current rating (I_FSM) of 30 A, tested using an 8.3 ms single half-sine wave superimposed on rated load, per JEDEC standards. This rating ensures robustness during power-up inrush, short-circuit events, or motor stall conditions - a key reliability feature validated in the Absolute Maximum Ratings table for the SF12G-K.

SF12G-K Specifications

Product attributes: Attribute value

Manufacturer:: Taiwan Semiconductor Corporation

Series:: -

Package/Case:: DO-204AL, DO-41, Axial

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Standard

Voltage - DC Reverse (Vr) (Max):: 100 V

Current - Average Rectified (Io):: 1A

Voltage - Forward (Vf) (Max) @ If:: 950 mV @ 1 A

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

Reverse Recovery Time (trr):: 35 ns

Current - Reverse Leakage @ Vr:: 5 µA @ 100 V

Capacitance @ Vr, F:: 20pF @ 4V, 1MHz

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-204AL (DO-41)

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

SF12G-K FAQ

1.How can I place an order for SF12G-K through Aetrix?

Please submit a Request for Quotation (RFQ) for SF12G-K 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 SF12G-K reliable?

The price and inventory of SF12G-K are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SF12G-K is usually 5 days.

3.What payment methods are accepted for SF12G-K?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SF12G-K transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SF12G-K?

SF12G-K orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SF12G-K 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 SF12G-K?

For technical support, including SF12G-K datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SF12G-K requirements.

6.How does Aetrix verify that SF12G-K is sourced from the original manufacturer or authorized distributors?

All SF12G-K 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 SF12G-K meets industry standards.

7.What is the process for return or replacement of SF12G-K?

All SF12G-K units undergo pre-shipment inspection (PSI). If there is an issue with SF12G-K, 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 SF12G-K part is unused and in its original packaging.

Return procedure for SF12G-K:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…