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

Vishay Siliconix IRFD420

Name: IRFD420
Brand: Vishay Siliconix
SKU: IRFD420
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRFD420

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

Package:: 4-DIP (0.300", 7.62mm)

Datasheet:: IRFD420.pdf

Description:: MOSFET N-CH 500V 370MA 4DIP

Quantity:: RFQ Add To RFQ list

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Product details

Overview

IRFD420 from Vishay Siliconix is a 500 V, 0.37 A N-channel power MOSFET in HVMDIP package, featuring 3.0 Ω R_DS(on) at V_GS = 10 V, 24 nC total gate charge, and repetitive avalanche rating-designed for low-power flyback converters, relay drivers, and solid-state switching in industrial control modules.

For engineers reviewing the IRFD420 datasheet, IRFD420 pinout, IRFD420 application, or IRFD420 equivalent, key selection considerations include its 1 W power dissipation limit, dual-drain thermal path, 3.5 V/ns peak diode recovery dV/dt, and compatibility with automatic insertion and end-stacking PCB assembly processes.

Technical Context

This discrete N-channel enhancement-mode MOSFET uses planar V-groove silicon technology optimized for ruggedness and fast switching in unclamped inductive load circuits. Its design supports repetitive avalanche operation up to 0.37 A and single-pulse energy of 51 mJ, with body diode reverse recovery time (260–520 ns) and Q_rr (0.70–1.4 μC) specified under controlled dI/dt conditions.

The device operates across –55 °C to +150 °C junction temperature range and features ±20 V gate-source voltage tolerance, 2.0–4.0 V threshold voltage, and low gate leakage (<±100 nA), enabling simple drive requirements with standard logic-level gate drivers in low-duty-cycle switching applications.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	500 V - supports primary-side switching in offline AC/DC converters up to 380 V DC bus
R_DS(on)	3.0 Ω @ V_GS = 10 V - enables 0.37 A continuous drain current at 1 W ambient-rated dissipation
Q_g	24 nC - determines gate drive power and switching loss in 20–100 kHz SMPS designs
E_AS	51 mJ - specifies single-pulse unclamped inductive energy handling without failure
R_thJA	120 °C/W - defines thermal rise from junction to ambient in free-air, non-heatsinked DIP layout
V_SD	1.6 V @ I_S = 0.37 A - forward voltage of integral body diode during synchronous rectification or freewheeling
dV/dt	3.5 V/ns - maximum tolerable rate of voltage rise across drain-source during diode recovery

Pinout & Package

The IRFD420 is housed in a 4-pin HVMDIP (High Voltage Mini-DIP) package with dual drain leads serving as thermal and electrical connection points. Package dimensions: 8.38 mm × 10.79 mm × 7.36 mm (L × W × H), 0.100" pin pitch, lead-free (PbF) finish per IRFD420PbF ordering code.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Drain)	Main current-carrying terminal	Connected internally to one half of dual-drain structure; used for high-voltage switching node attachment
Pin 2 (Gate)	Control input	Receives gate drive signal; requires ≤±20 V bias; low 3.3 nC Q_gs enables fast turn-on
Pin 3 (Source)	Reference and return path	Common reference for gate drive and load current return; ties to system ground or low-side switch node
Pin 4 (Drain)	Main current-carrying terminal	Electrically tied to Pin 1 internally; provides second thermal conduction path to PCB copper pour or heatsink

Key Features

Feature	Design Value
Repetitive avalanche rated	Enables reliable operation under transient overcurrents without derating, supporting robust protection in relay coil snubbing
Dynamic dV/dt rated	3.5 V/ns capability prevents false turn-on during high-slew-rate voltage transients in inductive loads
Dual drain thermal path	Reduces effective R_thJA by distributing heat across two pins, supporting 1 W dissipation in compact DIP footprint
End stackable package	Allows vertical stacking of multiple IRFD420 units on same PCB area for parallel current sharing or redundancy
Low Q_gd/Q_g ratio	13/24 = 54% - improves hard-switching efficiency and reduces Miller-induced oscillation risk

Applications

AC/DC Flyback Converter Primary Switch	Industrial Relay Driver
Use Scenario: Low-cost, low-power offline SMPS for auxiliary supplies in PLCs and sensor transmitters. IC Role / Device Role / Timing Role: Primary-side high-voltage switch operating at 60–100 kHz with discontinuous conduction mode. Use Value: 500 V V_DS and 51 mJ E_AS ensure safe operation during transformer reset spikes and line surges.	Use Scenario: Solid-state replacement for electromechanical relays controlling 24–48 V DC solenoids and valves. IC Role / Device Role / Timing Role: Low-duty-cycle, high-voltage switching element with integrated body diode for inductive kickback clamping. Use Value: Repetitive avalanche rating allows direct absorption of L·di/dt energy without external TVS, reducing BOM count.
LED String Power Switch	Microcontroller-Driven Load Control
Use Scenario: Constant-current LED driver stage for signage or indicator panels powered from 12–24 V DC rails. IC Role / Device Role / Timing Role: PWM-controlled high-side or low-side switch regulating average LED current. Use Value: 3.0 Ω R_DS(on) limits conduction loss to <100 mW at 180 mA, enabling thermally stable operation in sealed enclosures.	Use Scenario: General-purpose digital output port for microcontrollers interfacing with resistive or small inductive loads. IC Role / Device Role / Timing Role: Level-shifting, current-amplifying interface between 3.3/5 V GPIO and 5–24 V external loads. Use Value: Simple gate drive (no level shifter needed for 5 V logic), low 24 nC Q_g, and ±20 V V_GS tolerance simplify firmware-safe control.

AC/DC Flyback Converter Primary Switch

Industrial Relay Driver

Use Scenario: Low-cost, low-power offline SMPS for auxiliary supplies in PLCs and sensor transmitters.

IC Role / Device Role / Timing Role: Primary-side high-voltage switch operating at 60–100 kHz with discontinuous conduction mode.

Use Value: 500 V V_DS and 51 mJ E_AS ensure safe operation during transformer reset spikes and line surges.

Use Scenario: Solid-state replacement for electromechanical relays controlling 24–48 V DC solenoids and valves.

IC Role / Device Role / Timing Role: Low-duty-cycle, high-voltage switching element with integrated body diode for inductive kickback clamping.

Use Value: Repetitive avalanche rating allows direct absorption of L·di/dt energy without external TVS, reducing BOM count.

LED String Power Switch

Microcontroller-Driven Load Control

Use Scenario: Constant-current LED driver stage for signage or indicator panels powered from 12–24 V DC rails.

IC Role / Device Role / Timing Role: PWM-controlled high-side or low-side switch regulating average LED current.

Use Value: 3.0 Ω R_DS(on) limits conduction loss to <100 mW at 180 mA, enabling thermally stable operation in sealed enclosures.

Use Scenario: General-purpose digital output port for microcontrollers interfacing with resistive or small inductive loads.

IC Role / Device Role / Timing Role: Level-shifting, current-amplifying interface between 3.3/5 V GPIO and 5–24 V external loads.

Use Value: Simple gate drive (no level shifter needed for 5 V logic), low 24 nC Q_g, and ±20 V V_GS tolerance simplify firmware-safe control.

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
STP1NK60Z	600 V V_DS, 0.36 A I_D, 5.5 Ω R_DS(on), TO-92 package	Higher voltage rating but higher on-resistance and different thermal path; no dual drain	Preferred where 600 V margin is required and PCB space allows TO-92 mounting
FQP4N50	500 V V_DS, 4.0 A I_D, 1.4 Ω R_DS(on), TO-220 package	Higher current and lower R_DS(on), but larger footprint and no avalanche rating	Selected when >0.37 A continuous current or heatsink-based thermal management is needed

Compared with STP1NK60Z and FQP4N50, the IRFD420 offers unique value in machine-insertable HVMDIP packaging with dual-drain thermal conduction and verified repetitive avalanche performance-making it optimal for space-constrained, low-power industrial controls where reliability under transient stress is critical.

Availability

IRFD420 is available at Aetrix Electronics and suitable for AC/DC flyback converters, industrial relay drivers, and microcontroller-driven load control requiring stable component supply and long-term manufacturability.

Supply support for IRFD420 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, precision, and reliability.

The IRFD420 belongs to Vishay's third-generation high-voltage power MOSFET family, engineered specifically for cost-sensitive, low-power industrial and control applications demanding automatic assembly compatibility and transient robustness.

FAQ

What is the maximum continuous drain current for the IRFD420 at 100 °C ambient temperature?

The IRFD420 supports 0.23 A continuous drain current at TA = 100 °C, derived from its 0.37 A rating at 25 °C and linear derating factor of 0.0083 W/°C. This reflects thermal limitation in free-air conditions without heatsinking. The IRFD420 must be operated within its Safe Operating Area (SOA) curve-especially critical during pulse loads-and its dual-drain package helps distribute thermal load across two PCB pads to improve local cooling.

Does the IRFD420 have an integrated body diode, and what are its key parameters?

Yes, the IRFD420 includes an integral source-drain body diode rated for 0.37 A continuous forward current and 5.0 A pulsed current. Its forward voltage is 1.6 V at IS = 0.37 A and TJ = 25 °C, with reverse recovery time trr of 260–520 ns and Qrr of 0.70–1.4 μC under IF = 2.1 A and dI/dt = 100 A/μs. These values are critical for designing snubberless inductive load interfaces and evaluating commutation losses in the IRFD420.

Can the IRFD420 be used in avalanche mode, and what are the limits?

Yes, the IRFD420 is explicitly rated for repetitive avalanche operation with IAR = 0.37 A and EAR = 0.10 mJ per pulse, and single-pulse EAS = 51 mJ. Avalanche testing follows standardized unclamped inductive conditions (VDD = 50 V, L = 40 mH, Rg = 25 Ω, IAS = 1.5 A). Operation beyond these validated limits risks parametric shift or failure. Designers must verify all avalanche use cases against the IRFD420 SOA and thermal response curves in the official datasheet.

What is the gate threshold voltage range for the IRFD420, and how does it affect drive compatibility?

The IRFD420 has a gate-source threshold voltage VGS(th) ranging from 2.0 V to 4.0 V at ID = 250 μA, making it compatible with standard 5 V TTL/CMOS logic drivers without level shifting. However, full enhancement requires VGS ≥ 10 V to achieve rated RDS(on) = 3.0 Ω. At VGS = 5 V, RDS(on) rises significantly-designers should confirm switching speed and conduction loss trade-offs in their specific IRFD420 application before committing to sub-10 V gate drive.

Is the IRFD420 suitable for surface-mount assembly, or is it through-hole only?

The IRFD420 is exclusively offered in the through-hole HVMDIP package and is not available in SMT variants. Its 4-pin DIP footprint with 0.100" pin spacing is designed for wave soldering and automatic insertion equipment. While hand-soldering is feasible, reflow or paste-in-hole processes are not supported. For SMT alternatives, designers should evaluate Vishay's SiHP series or cross-reference to compatible SO-8 or PowerPAK packages-but those are distinct part numbers, not drop-in replacements for the IRFD420.

IRFD420 Specifications

Product attributes: Attribute value

Manufacturer:: Vishay Siliconix

Series:: -

Package/Case:: 4-DIP (0.300", 7.62mm)

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 500 V

Current - Continuous Drain (Id) @ 25°C:: 370mA (Ta)

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

Rds On (Max) @ Id, Vgs:: 3Ohm @ 220mA, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 24 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 360 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 1W (Ta)

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: 4-HVMDIP

IRFD420 FAQ

1.How can I place an order for IRFD420 through Aetrix?

Please submit a Request for Quotation (RFQ) for IRFD420 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 IRFD420 reliable?

The price and inventory of IRFD420 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRFD420 is usually 5 days.

3.What payment methods are accepted for IRFD420?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRFD420 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRFD420?

IRFD420 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRFD420 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 IRFD420?

For technical support, including IRFD420 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRFD420 requirements.

6.How does Aetrix verify that IRFD420 is sourced from the original manufacturer or authorized distributors?

All IRFD420 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 IRFD420 meets industry standards.

7.What is the process for return or replacement of IRFD420?

All IRFD420 units undergo pre-shipment inspection (PSI). If there is an issue with IRFD420, 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 IRFD420 part is unused and in its original packaging.

Return procedure for IRFD420:

1.Submit a request within 90 days.

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

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