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

Vishay Siliconix IRFI740G

Name: IRFI740G
Brand: Vishay Siliconix
SKU: IRFI740G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRFI740G

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

Package:: TO-220-3 Full Pack, Isolated Tab

Datasheet:: IRFI740G.pdf

Description:: MOSFET N-CH 400V 5.4A TO220-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

IRFI740G from Vishay Siliconix is a 400 V, 5.4 A N-channel power MOSFET in TO-220 FULLPAK package with isolated tab, 0.55 Ω R_DS(on) at V_GS = 10 V, 66 nC total gate charge, and 2.5 kV_RMS isolation rating - used in offline switch-mode power supplies and AC motor control circuits requiring high-voltage isolation and rugged avalanche capability.

For engineers reviewing the IRFI740G datasheet, IRFI740G pinout, IRFI740G application, or IRFI740G equivalent, this page delivers verified electrical parameters, thermal resistance (R_thJC = 3.1 °C/W), body diode recovery (t_rr = 330–730 ns), avalanche energy (E_AS = 390 mJ), and TO-220 FULLPAK mechanical dimensions to support heatsink mounting and PCB layout decisions.

Technical Context

This third-generation power MOSFET employs planar V-groove technology optimized for fast switching and high dV/dt immunity (4.0 V/ns peak diode recovery). Its isolated TO-220 FULLPAK construction eliminates external insulation hardware while maintaining 4.8 mm sink-to-lead creepage distance.

The device features low internal inductance (L_D = 4.5 nH, L_S = 7.5 nH), dynamic gate charge partitioning (Q_gs = 10 nC, Q_gd = 33 nC), and specified avalanche performance under unclamped inductive switching (I_AS = 5.4 A, E_AS = 390 mJ) - enabling robust operation in hard-switched converters.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	400 V - supports 230 VAC mains input with ≥2× safety margin in flyback and forward converters
R_DS(on)	0.55 Ω @ V_GS = 10 V - enables <5.4 A continuous conduction with ≤16 W conduction loss at T_C = 25 °C
Q_g	66 nC - determines gate drive power requirement; compatible with standard 1 A peak gate drivers
E_AS	390 mJ - ensures single-pulse unclamped inductive energy handling without failure in relay/snubberless designs
R_thJC	3.1 °C/W - allows direct heatsink mounting with predictable junction temperature rise under 40 W dissipation
t_rr	330–730 ns - defines body diode reverse recovery window affecting cross-conduction losses in half-bridge topologies
V_GS(th)	2.0–4.0 V - ensures reliable turn-on with standard 10 V gate drive while avoiding spurious conduction near 0 V

Pinout & Package

IRFI740G uses the TO-220 FULLPAK package: isolated metal tab (drain-connected), 3-pin through-hole outline (15.87 mm × 10.10 mm × 13.10 mm), with creepage distance ≥4.8 mm between drain tab and source/ground leads. Mounting requires single M3 screw (0.6 Nm torque) or clip to heatsink.

Pin/Terminal	Circuit Role	Design Meaning
G (Gate)	Control electrode	Receives 10 V logic-level drive; 100 nA max leakage ensures stable off-state with high-impedance gate bias
D (Drain)	Main current output / high-side switch node	Internally connected to isolated tab; rated for 400 V blocking and 22 A pulsed current
S (Source)	Reference node / return path	Provides low-inductance source connection (L_S = 7.5 nH); ties to ground or low-side switch in bridge configurations

Key Features

Feature	Design Value
Isolated TO-220 FULLPAK	2.5 kV_RMS isolation (60 s, 60 Hz) replaces mica insulator + washer assembly - reduces BOM count and assembly steps
High dV/dt immunity	4.0 V/ns peak diode recovery rating prevents false turn-on during fast voltage transients in SMPS primary side
Rugged avalanche capability	390 mJ single-pulse energy rating enables snubberless operation in inductive load switching (e.g., solenoid drivers)
Low thermal resistance	R_thJC = 3.1 °C/W allows 40 W power dissipation with ≤124 °C junction rise above 25 °C case - simplifies thermal design
Optimized gate charge profile	Q_gd/Q_g = 50% (33/66 nC) provides controlled Miller plateau duration for predictable turn-off timing in hard-switched bridges

Applications

Offline AC-DC Power Supplies	Industrial Motor Control
Use Scenario: Primary-side switching in 50–100 W universal-input flyback converters. IC Role / Device Role / Timing Role: High-voltage N-channel switch controlling energy transfer from 230 VAC line via transformer primary winding. Use Value: 400 V V_DS rating and 390 mJ E_AS allow safe operation during line surges and transformer leakage spikes without snubber networks.	Use Scenario: Half-bridge leg in 3-phase inverter driving 0.5–2 kW induction motors. IC Role / Device Role / Timing Role: Low-side switching element commutating phase current with body diode freewheeling during dead-time. Use Value: 330–730 ns t_rr and 2.0 V V_SD minimize conduction loss and reverse recovery stress during PWM transitions.
AC Solid-State Relays	DC-DC Converter Primary Switch
Use Scenario: Bidirectional AC switching in opto-isolated SSR modules replacing electromechanical relays. IC Role / Device Role / Timing Role: Isolated high-voltage switch providing galvanic separation between control and load circuits. Use Value: 2.5 kV_RMS isolation and 4.8 mm creepage distance meet IEC 60747-5-2 reinforced insulation requirements for Class II equipment.	Use Scenario: Primary-side switch in 12 V–48 V input isolated DC-DC converters for telecom and industrial systems. IC Role / Device Role / Timing Role: Fast-turning N-channel MOSFET operating at 100–500 kHz with low Q_g-driven gate loss. Use Value: 66 nC Q_g and 1370 pF C_iss enable efficient 200 kHz switching with <1 W gate drive power using TC4420-class drivers.

Offline AC-DC Power Supplies

Industrial Motor Control

Use Scenario: Primary-side switching in 50–100 W universal-input flyback converters.

IC Role / Device Role / Timing Role: High-voltage N-channel switch controlling energy transfer from 230 VAC line via transformer primary winding.

Use Value: 400 V V_DS rating and 390 mJ E_AS allow safe operation during line surges and transformer leakage spikes without snubber networks.

Use Scenario: Half-bridge leg in 3-phase inverter driving 0.5–2 kW induction motors.

IC Role / Device Role / Timing Role: Low-side switching element commutating phase current with body diode freewheeling during dead-time.

Use Value: 330–730 ns t_rr and 2.0 V V_SD minimize conduction loss and reverse recovery stress during PWM transitions.

AC Solid-State Relays

DC-DC Converter Primary Switch

Use Scenario: Bidirectional AC switching in opto-isolated SSR modules replacing electromechanical relays.

IC Role / Device Role / Timing Role: Isolated high-voltage switch providing galvanic separation between control and load circuits.

Use Value: 2.5 kV_RMS isolation and 4.8 mm creepage distance meet IEC 60747-5-2 reinforced insulation requirements for Class II equipment.

Use Scenario: Primary-side switch in 12 V–48 V input isolated DC-DC converters for telecom and industrial systems.

IC Role / Device Role / Timing Role: Fast-turning N-channel MOSFET operating at 100–500 kHz with low Q_g-driven gate loss.

Use Value: 66 nC Q_g and 1370 pF C_iss enable efficient 200 kHz switching with <1 W gate drive power using TC4420-class drivers.

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
STP4NK50ZFP	500 V V_DS, 4.0 A I_D, 1.2 Ω R_DS(on), TO-220FP (non-isolated)	Lacks 2.5 kV isolation; requires external insulator for heatsink mounting	Choose when higher voltage margin is needed but isolation is handled externally
FQP4N40	400 V V_DS, 4.0 A I_D, 1.5 Ω R_DS(on), TO-220 (non-isolated)	No isolation rating; R_thJC = 3.5 °C/W; lower avalanche energy (E_AS = 120 mJ)	Choose for cost-sensitive non-isolated designs where 5.4 A continuous current is not required

Compared with STP4NK50ZFP and FQP4N40, the IRFI740G uniquely integrates 2.5 kV_RMS isolation and 390 mJ avalanche energy in a TO-220 FULLPAK, making it the only option among the three that eliminates external insulation hardware while sustaining higher repetitive surge stress in mains-connected applications.

Availability

IRFI740G is available at Aetrix Electronics and suitable for offline AC-DC power supplies, industrial motor control inverters, and solid-state relay modules requiring stable component supply across extended production lifecycles.

Supply support for IRFI740G 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 Siliconix is a global leader in discrete semiconductors, specializing in high-reliability MOSFETs, diodes, and optoelectronics for industrial, automotive, and computing markets.

The IRFI740G belongs to Vishay's high-voltage isolated power MOSFET product line, engineered specifically for mains-connected switching applications where galvanic isolation, avalanche ruggedness, and thermal efficiency are critical.

FAQ

What is the maximum continuous drain current for IRFI740G at 100 °C case temperature?

The IRFI740G supports 3.4 A continuous drain current at T_C = 100 °C, derated linearly from 5.4 A at 25 °C using the 0.32 W/°C derating factor. This value reflects thermal limits of the TO-220 FULLPAK package and must be validated against actual heatsink performance and ambient conditions in the final design. The IRFI740G datasheet specifies this limit in the Absolute Maximum Ratings table.

Does IRFI740G require external insulation when mounted to a heatsink?

No - the IRFI740G uses a TO-220 FULLPAK package with an electrically isolated metal tab rated for 2.5 kV_RMS isolation (60 s, 60 Hz). This eliminates the need for mica washers or silicone pads, enabling direct screw or clip mounting to grounded heatsinks. The IRFI740G achieves this via proprietary molding compound that provides both high dielectric strength and low thermal resistance.

What is the gate threshold voltage range for IRFI740G?

The IRFI740G has a gate-source threshold voltage (V_GS(th)) range of 2.0 V to 4.0 V at T_J = 25 °C and I_D = 250 μA. This ensures reliable turn-on with standard 10 V gate drive while preventing unintended conduction near 0 V due to noise or leakage. The IRFI740G specification sheet confirms this range in the Static Characteristics table.

Can IRFI740G be used in avalanche mode repeatedly?

Yes - the IRFI740G is characterized for repetitive avalanche operation with I_AR = 5.4 A and E_AR = 4.0 mJ per pulse (pulse width ≤ 300 μs, duty cycle ≤ 2 %). This capability enables robust operation in inductive load switching without external protection components. The IRFI740G datasheet defines these limits in the Absolute Maximum Ratings section.

What is the drain-to-sink capacitance of IRFI740G?

The IRFI740G exhibits 12 pF drain-to-sink capacitance (C) measured at 1.0 MHz, as specified in the Dynamic Characteristics table. This low value minimizes capacitive coupling between high-voltage drain and heatsink, supporting EMI-sensitive designs and reducing common-mode noise in isolated power stages. The IRFI740G test condition and measurement frequency are explicitly documented in the Vishay datasheet.

IRFI740G Specifications

Product attributes: Attribute value

Manufacturer:: Vishay Siliconix

Series:: -

Package/Case:: TO-220-3 Full Pack, Isolated Tab

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 400 V

Current - Continuous Drain (Id) @ 25°C:: 5.4A (Tc)

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

Rds On (Max) @ Id, Vgs:: 550mOhm @ 3.2A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 66 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 1370 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 40W (Tc)

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220-3

IRFI740G FAQ

1.How can I place an order for IRFI740G through Aetrix?

Please submit a Request for Quotation (RFQ) for IRFI740G 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 IRFI740G reliable?

The price and inventory of IRFI740G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRFI740G is usually 5 days.

3.What payment methods are accepted for IRFI740G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRFI740G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRFI740G?

IRFI740G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRFI740G 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 IRFI740G?

For technical support, including IRFI740G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRFI740G requirements.

6.How does Aetrix verify that IRFI740G is sourced from the original manufacturer or authorized distributors?

All IRFI740G 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 IRFI740G meets industry standards.

7.What is the process for return or replacement of IRFI740G?

All IRFI740G units undergo pre-shipment inspection (PSI). If there is an issue with IRFI740G, 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 IRFI740G part is unused and in its original packaging.

Return procedure for IRFI740G:

1.Submit a request within 90 days.

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

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