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

Infineon Technologies IRF3704SPBF

Name: IRF3704SPBF
Brand: Infineon Technologies
SKU: IRF3704SPBF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRF3704SPBF

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

Package:: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB

Datasheet:: IRF3704SPBF.pdf

Description:: MOSFET N-CH 20V 77A D2PAK

Quantity:: RFQ Add To RFQ list

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Product details

Overview

IRF3704SPBF from Infineon Technologies (formerly International Rectifier) is a 20V, 77A, 9.0mΩ N-channel enhancement-mode HEXFET Power MOSFET in TO-220AB package, optimized for high-frequency synchronous rectification in isolated DC-DC converters and buck regulators for telecom and industrial power supplies.

For engineers reviewing the IRF3704SPBF datasheet, IRF3704SPBF pinout, IRF3704SPBF application, or IRF3704SPBF equivalent, key selection criteria include its ultra-low R_DS(on), fully characterized avalanche capability (216 mJ), fast switching (t_r = 98 ns), low gate charge (Q_g = 19 nC), and robust thermal performance (R_θJC = 1.73 °C/W).

Technical Context

This MOSFET employs planar silicon HEXFET architecture with optimized cell pitch and trench-free die design to achieve sub-10mΩ on-resistance at V_GS = 10V while maintaining high dV/dt immunity and rugged unclamped inductive switching capability. Its body diode exhibits low V_SD (0.88 V @ 35.5A, T_J = 25°C) and controlled reverse recovery (Q_rr = 45–68 nC).

The device is specified for operation across –55°C to +175°C junction temperature, with gate threshold voltage (V_GS(th)) tightly distributed between 1.0 V and 3.0 V, enabling reliable turn-on with 4.5V logic-level drive. Dynamic parameters-including C_iss = 1996 pF and Cr_ss = 155 pF-are characterized at 1 MHz and V_DS = 10V for accurate hard-switching loss modeling.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	20 V - Maximum blocking voltage for low-voltage synchronous rectifier or primary-side switch in 12V-input systems.
R_DS(on) max	9.0 mΩ @ V_GS = 10V - Enables <1W conduction loss at 33A RMS, critical for high-efficiency telecom PSUs.
I_D continuous	77 A @ T_C = 25°C - Supports high-current output stages without paralleling in compact PCB layouts.
Q_g	19 nC - Reduces gate drive power and enables >500 kHz switching with standard 1A drivers.
E_AS	216 mJ - Guarantees single-pulse avalanche survivability during transient overvoltage events in flyback or LLC topologies.
t_r/t_f	98 ns / 5.0 ns - Fast edge rates minimize switching transition losses and EMI generation in high-frequency SMPS.
V_GS(th)	1.0–3.0 V - Ensures predictable turn-on with 3.3V/5V microcontroller GPIO or PWM controller outputs.

Pinout & Package

IRF3704SPBF is housed in a through-hole TO-220AB package with exposed drain tab for heatsinking. Pin 1 = Gate, Pin 2 = Drain, Pin 3 = Source, Pin 4 = Drain (dual-drain configuration for improved current sharing and thermal path).

Pin/Terminal	Circuit Role	Design Meaning
1 (Gate)	Control electrode	Receives gate drive signal; requires low-impedance path to minimize ringing due to Q_gd = 6.4 nC.
2 (Drain)	Main current sink	Connected to high-side node or transformer secondary; electrically tied to metal tab for thermal conduction.
3 (Source)	Reference node	Serves as return path for load current and gate drive reference; layout must minimize inductance to suppress shoot-through.
4 (Drain)	Secondary current sink	Parallel drain connection reduces package inductance and improves current distribution under high di/dt conditions.

Key Features

Feature	Design Value
Ultra-low gate impedance	Enables stable high-speed switching without external gate resistors in most 500 kHz–1 MHz designs.
Fully characterized avalanche	216 mJ single-pulse rating verified per JEDEC JESD24-11, eliminating need for external snubbers in inductive loads.
Lead-free (PbF) construction	Complies with RoHS Directive 2011/65/EU and JEDEC JS709B, suitable for lead-free reflow and wave soldering.
Optimized body diode	Q_rr = 45–68 nC and t_rr = 38–62 ns support zero-voltage switching (ZVS) in resonant topologies.
Thermal robustness	R_θJC = 1.73 °C/W allows >60W dissipation with modest heatsinking-critical for space-constrained telecom bricks.

Applications

Telecom DC-DC Converters

Industrial Buck Regulators

Use Scenario: 48V-to-12V isolated forward converter in 1RU server power supply with 80 PLUS Titanium efficiency target.

IC Role / Device Role: Synchronous rectifier on secondary side, replacing Schottky diode to reduce conduction loss by >40%.

Use Value: Achieves 0.8 mΩ effective R_DS(on) at 12V output, cutting rectifier loss from 3.2W to 1.1W at 60A load.

Use Scenario: High-current 5V/30A point-of-load regulator for FPGA core voltage in factory automation PLC.

IC Role / Device Role: Low-side switch in synchronous buck topology operating at 600 kHz with ceramic output capacitors.

Use Value: 9.0 mΩ R_DS(on) limits I²R loss to 0.81W at 30A, enabling 25°C rise on 2oz copper with minimal heatsink.

High-Frequency Isolated Adapters

Motor Drive Half-Bridge Legs

Use Scenario: 65W GaN-based USB-C PD adapter with active clamp flyback and synchronous rectification.

IC Role / Device Role: Secondary-side MOSFET driven by self-driven or controller-synchronized gate signal.

Use Value: Fast t_f = 5.0 ns and low Q_oss = 16–24 nC minimize dead-time losses and improve light-load efficiency.

Use Scenario: 24V BLDC motor driver stage for HVAC fan control requiring >15A continuous phase current.

IC Role / Device Role: Low-side switch in half-bridge configuration with bootstrap gate drive.

Use Value: V_GS(th) range ensures clean turn-on even with bootstrap droop to 4.5V, preventing shoot-through risk.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
IRL3705PBF	R_DS(on) = 12 mΩ @ 10V; higher Q_g = 25 nC; same TO-220AB package	Lower current rating (65A vs. 77A); less suitable for >500 kHz operation due to slower t_r	Prefer when cost sensitivity outweighs efficiency targets and peak current stays below 60A.
STP20NF20	R_DS(on) = 100 mΩ @ 10V; V_DS = 200V; TO-220FP package with insulated tab	Higher voltage rating but 11× higher on-resistance; unsuitable for high-current low-V_DS apps	Select only if system requires 200V blocking and thermal constraints allow higher conduction loss.

Compared with IRL3705PBF and STP20NF20, IRF3704SPBF delivers the lowest conduction and switching losses in 20V, high-current synchronous rectification-making it optimal for telecom and high-density industrial SMPS where efficiency and thermal headroom are critical.

Availability

IRF3704SPBF is available at Aetrix Electronics and suitable for telecom DC-DC converters, industrial buck regulators, and high-frequency isolated adapters requiring stable component supply and full RoHS compliance.

Supply support for IRF3704SPBF 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 leader specializing in power management, automotive, and industrial control ICs and discrete devices, with global manufacturing and quality certification to ISO 9001 and IATF 16949.

The HEXFET Power MOSFET product line was developed specifically for high-efficiency, high-reliability power conversion in telecom infrastructure, server PSUs, and industrial motor drives-emphasizing low R_DS(on), fast switching, and rugged avalanche performance.

FAQ

What is the maximum recommended gate drive voltage for IRF3704SPBF?

The absolute maximum V_GS is ±20 V per datasheet Absolute Maximum Ratings. For reliable long-term operation, gate drive should be limited to 10 V to avoid accelerated gate oxide degradation while ensuring full enhancement. Driving above 12 V yields diminishing R_DS(on) improvement (<2% reduction from 10 V to 15 V) and increases risk of overshoot-induced failure.

Can IRF3704SPBF be used in parallel configurations?

Yes-its positive temperature coefficient of R_DS(on) (see Fig 4) enables inherent current sharing. However, layout symmetry is critical: matched gate trace lengths, Kelvin source connections, and shared heatsink contact area are required. Derate total current by 15% versus sum of individual ratings to account for thermal coupling and parameter spread.

Does IRF3704SPBF have avalanche-rated capability?

Yes-datasheet specifies E_AS = 216 mJ (single-pulse, T_J = 25°C) and I_AR = 71 A, verified per JEDEC JESD24-11. This rating applies to unclamped inductive switching events only; repetitive avalanche is not guaranteed and requires detailed thermal analysis per application note AN-994.

What is the thermal resistance from junction to case (R_θJC) for IRF3704SPBF?

R_θJC is 1.73 °C/W maximum, measured from die junction to the center of the TO-220AB drain tab surface. This value assumes proper mounting with thermal grease and flat heatsink interface. PCB-mounted R_θJA is 40 °C/W, significantly lower than standard FR-4 board mount due to the dual-drain thermal path.

IRF3704SPBF Specifications

Product attributes: Attribute value

Manufacturer:: Infineon Technologies

Series:: HEXFET®

Package/Case:: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB

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):: 4.5V, 10V

Rds On (Max) @ Id, Vgs:: 9mOhm @ 15A, 10V

Vgs(th) (Max) @ Id:: 3V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 19 nC @ 4.5 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 1996 pF @ 10 V

FET Feature:: -

Power Dissipation (Max):: 87W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: D2PAK

IRF3704SPBF FAQ

1.How can I place an order for IRF3704SPBF through Aetrix?

Please submit a Request for Quotation (RFQ) for IRF3704SPBF 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 IRF3704SPBF reliable?

The price and inventory of IRF3704SPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRF3704SPBF is usually 5 days.

3.What payment methods are accepted for IRF3704SPBF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRF3704SPBF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRF3704SPBF?

IRF3704SPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRF3704SPBF 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 IRF3704SPBF?

For technical support, including IRF3704SPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRF3704SPBF requirements.

6.How does Aetrix verify that IRF3704SPBF is sourced from the original manufacturer or authorized distributors?

All IRF3704SPBF 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 IRF3704SPBF meets industry standards.

7.What is the process for return or replacement of IRF3704SPBF?

All IRF3704SPBF units undergo pre-shipment inspection (PSI). If there is an issue with IRF3704SPBF, 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 IRF3704SPBF part is unused and in its original packaging.

Return procedure for IRF3704SPBF:

1.Submit a request within 90 days.

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

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