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

Vishay Siliconix IRFI730G

Name: IRFI730G
Brand: Vishay Siliconix
SKU: IRFI730G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRFI730G

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

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

Datasheet:: IRFI730G.pdf

Description:: MOSFET N-CH 400V 3.7A TO220-3

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Product details

Overview

IRFI730G from Vishay Siliconix is a 400 V, 3.7 A N-channel power MOSFET in TO-220 FULLPAK package with isolated tab, 1.0 Ω R_DS(on) at V_GS = 10 V, 38 nC total gate charge, and 2.5 kV_RMS isolation rating - used in offline AC-DC flyback and forward converters requiring reinforced insulation.

For engineers reviewing the IRFI730G datasheet, IRFI730G pinout, IRFI730G application, or IRFI730G equivalent, this device is selected for high-voltage switching in industrial power supplies, LED drivers, and solenoid control where creepage >4.8 mm and low thermal resistance (R_thJC = 3.6 °C/W) are critical.

Technical Context

The IRFI730G employs a third-generation silicon process optimized for ruggedized avalanche performance (E_AS = 200 mJ) and dynamic dV/dt immunity (4.0 V/ns). Its isolated TO-220 FULLPAK construction eliminates external insulators while maintaining 3.6 °C/W junction-to-case thermal resistance.

It features a fast body diode (t_rr = 260–530 ns, Q_rr = 1.2–2.2 μC) and low gate charge profile (Q_gd/Q_g = 58 %), supporting efficient hard-switched topologies up to 100 kHz with minimal switching loss.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	400 V - supports 230 VAC mains-derived bus voltages with ≥2× safety margin
R_DS(on)	1.0 Ω @ V_GS = 10 V - enables <3.7 W conduction loss at 3.7 A continuous drain current
Q_g	38 nC - determines gate drive power requirement and switching speed in 50–100 kHz SMPS
E_AS	200 mJ - withstands unclamped inductive energy during startup/fault without failure
R_thJC	3.6 °C/W - allows 35 W dissipation with ≤126 °C temperature rise above heatsink
dV/dt Rating	4.0 V/ns - suppresses false turn-on in high-noise, high-dV/dt environments like motor drives
V_GS(th)	2.0–4.0 V - ensures reliable enhancement-mode turn-on with standard 10 V gate drivers

Pinout & Package

IRFI730G uses the TO-220 FULLPAK package: insulated metal tab (drain), 3-lead through-hole outline with 2.54 mm lead pitch, 4.8 mm sink-to-lead creepage, and 2.5 kV_RMS isolation per UL/IEC standards.

Pin/Terminal	Circuit Role	Design Meaning
G	Gate	Control terminal accepting 10 V logic-level drive; requires <38 nC charge for full enhancement
D	Drain	High-side switching node connected to insulated tab; rated for 400 V and 15 A pulsed
S	Source	Power return path; referenced to PCB ground; forms common node with body diode cathode

Key Features

Feature	Design Value
Isolated TO-220 FULLPAK	Eliminates mica washers and thermal pads - reduces assembly cost and thermal interface resistance by ~30 %
2.5 kV_RMS Isolation	Meets reinforced insulation requirements for Class I/II AC-DC adapters and industrial power supplies
Low R_thJC (3.6 °C/W)	Enables direct mounting to heatsink without thermal derating penalties typical of non-isolated TO-220
Fast Body Diode (t_rr = 260 ns typ.)	Reduces switching losses in discontinuous conduction mode (DCM) flyback and synchronous rectification
Avalanche-Rated (E_AS = 200 mJ)	Guarantees single-pulse robustness during transformer leakage energy discharge without external snubbers

Applications

Industrial AC-DC Power Supplies	LED Driver Circuits
Use Scenario: 30–60 W offline flyback converter powering PLC I/O modules with universal 85–265 VAC input. IC Role / Device Role / Timing Role: Primary-side high-side switch controlling energy transfer into transformer primary winding. Use Value: 400 V rating and 200 mJ avalanche capability prevent failure during line surges and transformer saturation events.	Use Scenario: Constant-current buck-boost LED driver for street lighting operating from 277 VAC line. IC Role / Device Role / Timing Role: High-side switch regulating average LED current via PWM dimming at 1–10 kHz. Use Value: 1.0 Ω R_DS(on) minimizes conduction loss across wide ambient temperature range (−40 to +85 °C).
Solenoid & Relay Drivers	DC Motor Control (Low-Power)
Use Scenario: 24 VDC industrial control panel driving 12 W solenoid valves with fast on/off cycling. IC Role / Device Role / Timing Role: Low-side switch sinking solenoid current; body diode provides freewheeling path. Use Value: 3.7 A continuous rating and 15 A pulsed current support 500 ms duty-cycle bursts without thermal shutdown.	Use Scenario: 24 V brushed DC motor controller in automated gate operator with H-bridge half-bridge stage. IC Role / Device Role / Timing Role: High-side switch in asymmetric H-bridge enabling bidirectional control with single-supply gate drive. Use Value: 4.8 mm creepage and reinforced isolation prevent arcing in humid outdoor enclosures.

Industrial AC-DC Power Supplies

LED Driver Circuits

Use Scenario: 30–60 W offline flyback converter powering PLC I/O modules with universal 85–265 VAC input.

IC Role / Device Role / Timing Role: Primary-side high-side switch controlling energy transfer into transformer primary winding.

Use Value: 400 V rating and 200 mJ avalanche capability prevent failure during line surges and transformer saturation events.

Use Scenario: Constant-current buck-boost LED driver for street lighting operating from 277 VAC line.

IC Role / Device Role / Timing Role: High-side switch regulating average LED current via PWM dimming at 1–10 kHz.

Use Value: 1.0 Ω R_DS(on) minimizes conduction loss across wide ambient temperature range (−40 to +85 °C).

Solenoid & Relay Drivers

DC Motor Control (Low-Power)

Use Scenario: 24 VDC industrial control panel driving 12 W solenoid valves with fast on/off cycling.

IC Role / Device Role / Timing Role: Low-side switch sinking solenoid current; body diode provides freewheeling path.

Use Value: 3.7 A continuous rating and 15 A pulsed current support 500 ms duty-cycle bursts without thermal shutdown.

Use Scenario: 24 V brushed DC motor controller in automated gate operator with H-bridge half-bridge stage.

IC Role / Device Role / Timing Role: High-side switch in asymmetric H-bridge enabling bidirectional control with single-supply gate drive.

Use Value: 4.8 mm creepage and reinforced isolation prevent arcing in humid outdoor enclosures.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP4NK40Z	400 V, 3.5 A, R_DS(on) = 1.2 Ω, no isolation, TO-220 non-FULLPAK	Requires external insulator; higher R_DS(on) increases conduction loss by ~20 %	Select when board-level isolation is already implemented and cost is prioritized over thermal performance.
FQP4N40	400 V, 3.8 A, R_DS(on) = 1.3 Ω, non-isolated, TO-220	Lacks 2.5 kV_RMS isolation and creepage compliance; unsuitable for reinforced insulation designs	Choose only for non-safety-critical DC-DC stages where external isolation is handled elsewhere.

Compared with STP4NK40Z and FQP4N40, the IRFI730G delivers lower thermal resistance and integrated isolation - reducing BOM count and improving reliability in safety-certified AC-DC systems without compromising voltage rating or current capability.

Availability

IRFI730G is available at Aetrix Electronics and suitable for industrial AC-DC power supplies, LED driver circuits, and solenoid/relay driver modules requiring stable component supply and long-term lifecycle support.

Supply support for IRFI730G 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 power MOSFETs, diodes, and optoelectronics with emphasis on ruggedness, efficiency, and reliability.

The IRFI730G belongs to Vishay's high-voltage isolated MOSFET product line, engineered specifically for safety-critical offline switching applications demanding reinforced insulation, high avalanche energy tolerance, and low thermal impedance.

FAQ

What is the maximum continuous drain current rating for the IRFI730G at 100 °C case temperature?

The IRFI730G has a maximum continuous drain current (I_D) of 2.3 A at T_C = 100 °C, derated linearly from 3.7 A at 25 °C using a factor of 0.28 W/°C. This reflects real-world thermal limits when mounted on a heatsink with limited surface area or airflow. The IRFI730G must be operated within this limit to avoid exceeding its 150 °C maximum junction temperature.

Does the IRFI730G require an external heatsink, and what is its thermal resistance junction-to-case?

Yes, the IRFI730G requires a heatsink for continuous operation above ~1.5 A due to its 35 W maximum power dissipation at T_C = 25 °C. Its junction-to-case thermal resistance (R_thJC) is 3.6 °C/W - measured from die to the isolated metal tab - enabling direct mounting to a heatsink without insulating hardware. This value is confirmed in the Vishay datasheet S21-0974-Rev. C.

What is the gate-source threshold voltage range for the IRFI730G, and how does it affect drive circuit design?

The IRFI730G has a gate-source threshold voltage (V_GS(th)) range of 2.0 V to 4.0 V at I_D = 250 μA. This means a minimum 5 V gate drive is recommended for reliable turn-on, but full enhancement requires 10 V to achieve the specified 1.0 Ω R_DS(on). Drive circuits must supply ≥10 V with sufficient peak current to deliver 38 nC gate charge within required switching times. The IRFI730G is not a logic-level MOSFET.

Can the IRFI730G be used in avalanche mode, and what is its rated single-pulse energy?

Yes, the IRFI730G is fully rated for single-pulse avalanche operation with E_AS = 200 mJ under defined test conditions (V_DD = 50 V, L = 25 mH, I_AS = 3.7 A). This rating is validated per JEDEC standards and allows safe operation during inductive turn-off transients without external snubbers. Repetitive avalanche is limited to I_AR = 3.7 A and E_AR = 3.5 mJ. The IRFI730G datasheet explicitly guarantees this performance.

What is the creepage distance between the drain tab and leads on the IRFI730G, and why is it important?

The IRFI730G provides a minimum sink-to-lead creepage distance of 4.8 mm, as verified in Vishay's TO-220 FULLPAK mechanical drawings. This meets reinforced insulation requirements for 250–300 V working voltage per IEC 60950-1 and IEC 62368-1. It eliminates need for slotting or air gaps on PCBs in AC-DC power supplies - a key enabler for compact, certified designs. The IRFI730G achieves this via molded isolation, not external hardware.

IRFI730G 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:: 3.7A (Tc)

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

Rds On (Max) @ Id, Vgs:: 1Ohm @ 2.1A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 38 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 700 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 35W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220-3

IRFI730G FAQ

1.How can I place an order for IRFI730G through Aetrix?

Please submit a Request for Quotation (RFQ) for IRFI730G 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 IRFI730G reliable?

The price and inventory of IRFI730G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRFI730G is usually 5 days.

3.What payment methods are accepted for IRFI730G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRFI730G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRFI730G?

IRFI730G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRFI730G 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 IRFI730G?

For technical support, including IRFI730G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRFI730G requirements.

6.How does Aetrix verify that IRFI730G is sourced from the original manufacturer or authorized distributors?

All IRFI730G 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 IRFI730G meets industry standards.

7.What is the process for return or replacement of IRFI730G?

All IRFI730G units undergo pre-shipment inspection (PSI). If there is an issue with IRFI730G, 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 IRFI730G part is unused and in its original packaging.

Return procedure for IRFI730G:

1.Submit a request within 90 days.

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

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