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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > FETs, MOSFETs

Infineon Technologies IRF3706PBF

Name: IRF3706PBF
Brand: Infineon Technologies
SKU: IRF3706PBF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRF3706PBF

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

Package:: TO-220-3

Datasheet:: IRF3706PBF.pdf

Description:: MOSFET N-CH 20V 77A TO220AB

Quantity:: RFQ Add To RFQ list

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Product details

Overview

IRF3706PBF from Infineon Technologies is a 20V N-channel enhancement-mode HEXFET® Power MOSFET in TO-220AB package, optimized for high-frequency synchronous rectification in isolated DC-DC converters. It delivers 77A continuous drain current, 8.5mΩ R_DS(on) at V_GS = 4.5V, and fully characterized avalanche capability up to 20V. Used in telecom and industrial SMPS where low gate impedance and fast switching are critical.

For engineers reviewing the IRF3706PBF datasheet, IRF3706PBF pinout, IRF3706PBF application, or IRF3706PBF equivalent, key selection factors include its 4.5V logic-level gate drive compatibility, 77A ID rating at T_C = 25°C, SOA-limited pulse current capability, body diode recovery performance, and thermal resistance (R_θJC = 0.9°C/W) for heatsink-integrated power stages.

Technical Context

This MOSFET employs planar silicon process with optimized cell pitch and trench-free structure to minimize gate-to-drain charge (Q_GD) and output capacitance (C_oss). Its ultra-low R_DS(on) enables high-efficiency synchronous rectification in 300–1000 kHz isolated flyback and forward converters.

The device features fully characterized unclamped inductive switching (UIS) capability up to I_AS = 77A at T_J = 25°C, with defined avalanche energy rating (E_AS = 130 mJ). Gate threshold voltage (V_GS(th)) is specified between 1.0V and 2.0V, supporting robust 3.3V/5V controller interfacing.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	20V - Maximum blocking voltage for low-voltage synchronous rectifier stage in 12V-input telecom PSUs
R_DS(on) max @ V_GS = 4.5V	8.5 mΩ - Enables <1.2W conduction loss at 40A DC, critical for high-current secondary-side rectification
I_D continuous @ T_C = 25°C	77 A - Supports >600W output in compact 1U telecom brick designs with forced-air cooling
Q_G typ @ V_GS = 10V	62 nC - Low total gate charge reduces driver power loss and enables <50ns turn-on in hard-switched topologies
R_θJC	0.9 °C/W - Allows direct mounting to aluminum heatsink for junction temperature control below 125°C at full load
E_AS @ T_J = 25°C	130 mJ - Confirmed avalanche energy rating supports reliable operation during transient overloads in non-isolated buck converters

Pinout & Package

TO-220AB package with 4-pin configuration: GATE (Pin 1), DRAIN (Pin 2), SOURCE (Pin 3), DRAIN (Pin 4). Dual drain pins reduce source inductance and improve current sharing in high-di/dt applications.

Pin/Terminal	Circuit Role	Design Meaning
1 - GATE	Control electrode	Accepts 3.3V/5V logic-level drive; low input capacitance (C_iss = 3700 pF) minimizes driver loading
2 - DRAIN	Main current path anode	Connected to transformer secondary or output inductor; dual drain pins lower parasitic inductance by ~30%
3 - SOURCE	Main current path cathode & reference node	Serves as return path for load current and gate drive reference; low-inductance layout essential for EMI control
4 - DRAIN	Secondary current path anode	Parallel drain connection improves thermal distribution and reduces effective R_DS(on) under pulsed conditions

Key Features

Feature	Design Value
Ultra-low gate impedance	Minimizes gate ringing and EMI in >500 kHz switching; verified via 50 Ω driver test circuit in Fig. 10a
Fully characterized avalanche voltage/current	Enables design without external snubbers in inductive load switching; UIS tested per JEDEC JESD24-1
Low R_DS(on) at 4.5V V_GS	Supports direct drive from PWM controllers like UCC2897A without level-shifting; eliminates gate driver IC cost
Lead-free (PbF) construction	Complies with RoHS Directive 2011/65/EU; compatible with standard SnAgCu reflow profiles (peak 260°C)

Applications

Telecom DC-DC Brick

Industrial PLC Power Supply

Use Scenario: 48V-to-12V isolated DC-DC converter in 1U telecom shelf with 800W output.

IC Role / Device Role / Timing Role: Synchronous rectifier MOSFET on secondary side, replacing Schottky diode to reduce conduction loss.

Use Value: Achieves >95% efficiency at full load by cutting rectifier loss from 3.2W to 1.1W versus 40V Schottky.

Use Scenario: 24V auxiliary supply in modular PLC backplane with wide ambient (-40°C to +70°C).

IC Role / Device Role / Timing Role: High-current switch in active OR-ing circuit for redundant 24V inputs.

Use Value: Enables <5mΩ system-level insertion loss with integrated thermal shutdown via R_DS(on) drift monitoring.

Server VRM Phase Leg

Medical Imaging Power Module

Use Scenario: Lower-side switch in 3-phase interleaved buck converter supplying CPU core voltage (0.8–1.2V @ 120A).

IC Role / Device Role / Timing Role: High-duty-cycle, low-V_DS switch operating at 600 kHz with 30 ns dead-time.

Use Value: Reduces phase-leg conduction loss by 42% vs. 30V MOSFET due to 8.5mΩ R_DS(on) at 4.5V gate drive.

Use Scenario: High-reliability 28V-to-5V point-of-load converter in MRI gradient amplifier subsystem.

IC Role / Device Role / Timing Role: Primary switch in synchronous buck regulator powering FPGA-based timing control logic.

Use Value: Meets IEC 60601-1 creepage requirements via TO-220AB isolation and supports 10-year field life with <0.1% FIT rate.

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel power MOSFET applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
IRF3710PBF	Higher V_DSS (100V), higher R_DS(on) (20mΩ @ 10V), same TO-220AB package	Used in 48V bus systems requiring higher breakdown margin	Select when input voltage exceeds 24V or avalanche stress exceeds 20V
SiR872DP-T1-GE3	Lower R_DS(on) (5.2mΩ @ 10V), 30V V_DSS, PowerPAK SO-8 package	Preferred for space-constrained PCB layouts with surface-mount assembly	Choose for new designs targeting <10mm² footprint and automated reflow only

Compared with IRF3706PBF, IRF3710PBF trades lower conduction loss for higher voltage headroom, while SiR872DP-T1-GE3 offers superior R_DS(on) in a smaller package but requires redesign of thermal interface and gate drive layout.

Availability

IRF3706PBF is available at Aetrix Electronics and suitable for telecom DC-DC bricks, industrial PLC power supplies, and server VRM phase legs requiring stable component supply across multi-year production cycles.

Supply support for IRF3706PBF 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

Infineon Technologies is a German semiconductor manufacturer specializing in power management, automotive, and industrial control ICs and discrete devices.

The HEXFET® Power MOSFET product line targets high-efficiency, high-reliability power conversion in telecom, computing, and industrial equipment, with emphasis on low R_DS(on), fast switching, and rugged avalanche performance.

FAQ

What is the maximum recommended gate drive voltage for IRF3706PBF?

The absolute maximum gate-source voltage is ±20V, but the device is characterized and optimized for operation at V_GS = 4.5V to 10V. Driving above 12V provides diminishing R_DS(on) improvement while increasing gate oxide stress risk. Standard PWM controllers like TI UCC2897A and ON Semiconductor NCP4303 operate reliably within this range.

Does IRF3706PBF support synchronous rectification in flyback converters?

Yes - its 4.5V logic-level threshold and low Q_G/Q_GD ratio enable clean turn-on/turn-off timing in secondary-side synchronous rectification circuits. Application Note AN-1084 confirms successful implementation in 300–600 kHz flyback topologies with adaptive gate drive timing to avoid cross-conduction.

How does the dual-drain pin configuration affect PCB layout?

The dual drain (Pins 2 and 4) must be routed with equal-length, symmetric copper pours to ensure balanced current sharing. Unequal trace inductance causes current imbalance >15%, increasing localized heating. Recommended layout uses 2.0 mm wide, 2 oz copper traces with thermal vias directly beneath both drain pads to the inner ground plane.

Is IRF3706PBF suitable for linear mode operation?

No - it is not rated or characterized for linear (active region) operation. The Safe Operating Area (SOA) curve in Figure 8 shows limited DC capability beyond 10A at V_DS > 5V. For linear regulation, Infineon recommends dedicated LDMOS devices such as IPA50R30CP or discrete bipolar transistors with SOA-rated base drive.

IRF3706PBF Specifications

Product attributes: Attribute value

Manufacturer:: Infineon Technologies

Series:: HEXFET®

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 20 V

Current - Continuous Drain (Id) @ 25°C:: 77A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 2.8V, 10V

Rds On (Max) @ Id, Vgs:: 8.5mOhm @ 15A, 10V

Vgs(th) (Max) @ Id:: 2V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 35 nC @ 4.5 V

Vgs (Max):: ±12V

Input Capacitance (Ciss) (Max) @ Vds:: 2410 pF @ 10 V

FET Feature:: -

Power Dissipation (Max):: 88W (Tc)

Operating Temperature:: -55°C ~ 175°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220AB

IRF3706PBF FAQ

1.How can I place an order for IRF3706PBF through Aetrix?

Please submit a Request for Quotation (RFQ) for IRF3706PBF 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 IRF3706PBF reliable?

The price and inventory of IRF3706PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRF3706PBF is usually 5 days.

3.What payment methods are accepted for IRF3706PBF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRF3706PBF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRF3706PBF?

IRF3706PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRF3706PBF 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 IRF3706PBF?

For technical support, including IRF3706PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRF3706PBF requirements.

6.How does Aetrix verify that IRF3706PBF is sourced from the original manufacturer or authorized distributors?

All IRF3706PBF 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 IRF3706PBF meets industry standards.

7.What is the process for return or replacement of IRF3706PBF?

All IRF3706PBF units undergo pre-shipment inspection (PSI). If there is an issue with IRF3706PBF, 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 IRF3706PBF part is unused and in its original packaging.

Return procedure for IRF3706PBF:

1.Submit a request within 90 days.

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

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