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

Vishay Siliconix IRF644

Name: IRF644
Brand: Vishay Siliconix
SKU: IRF644
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRF644

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

Package:: TO-220-3

Datasheet:: IRF644.pdf

Description:: MOSFET N-CH 250V 14A TO220AB

Quantity:: RFQ Add To RFQ list

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Product details

Overview

IRF644 from Vishay Siliconix is a 250 V, 14 A N-channel power MOSFET in TO-220AB package, featuring 0.28 Ω R_DS(on) at V_GS = 10 V, 68 nC total gate charge, and repetitive avalanche rating up to 14 A - widely used in switch-mode power supplies, motor controls, and DC-DC converters.

For engineers reviewing the IRF644 datasheet, IRF644 pinout, IRF644 application, or IRF644 equivalent, this page delivers verified electrical parameters, thermal performance data, body diode recovery characteristics, and real-world switching behavior under 125 V/7.9 A conditions - critical for high-reliability industrial power design.

Technical Context

The IRF644 employs planar vertical DMOS technology with optimized cell layout for low conduction loss and robust unclamped inductive switching (UIS) capability. Its 1.0 °C/W junction-to-case thermal resistance enables 125 W continuous dissipation at T_C = 25 °C when properly heatsinked.

Dynamic performance is defined by 11 ns turn-on delay, 24 ns rise time, 53 ns turn-off delay, and 49 ns fall time under standardized 9.1 Ω gate drive; body diode exhibits 250–500 ns reverse recovery time and 2.3–4.6 μC Q_rr at I_F = 7.9 A and dI/dt = 100 A/μs.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	250 V - supports input voltages up to 200 V DC bus in offline SMPS and motor drive applications
R_DS(on)	0.28 Ω @ V_GS = 10 V - limits conduction loss to ≤2.2 W at 9 A continuous drain current
Q_g	68 nC - determines gate drive power requirement and influences switching speed in hard-switched topologies
E_AS	550 mJ - enables reliable operation during transient overloads without external snubbers
T_J Range	−55 °C to +150 °C - qualified for industrial ambient environments and thermally demanding enclosures
I_D (T_C = 100 °C)	8.5 A - defines usable current derating for sustained operation in compact heatsink configurations
V_SD	1.8 V @ I_S = 14 A - impacts synchronous rectification efficiency and freewheeling losses in buck converters

Pinout & Package

IRF644 is housed in TO-220AB package: insulated tab, vertical mounting, 3-pin through-hole configuration with standard 2.54 mm lead pitch and 1.0 °C/W junction-to-case thermal resistance.

Pin/Terminal	Circuit Role	Design Meaning
Drain (D)	Main current-carrying terminal connected to internal MOSFET die substrate	Electrically tied to metal tab - requires isolation washer when mounted to grounded heatsink
Gate (G)	Control electrode modulating channel conductivity	High-impedance input requiring <100 nA leakage current; sensitive to ESD and ringing without proper gate resistor
Source (S)	Reference node for gate drive and return path for load current	Common connection point for low-side switching topology; referenced to ground in most buck and flyback designs

Key Features

Feature	Design Value
Repetitive avalanche rated	Withstands 14 A repetitive avalanche current and 13 mJ energy per pulse - eliminates need for external clamping in inductive load switching
Dynamic dV/dt rating	4.8 V/ns - prevents false turn-on during high-speed voltage transients in half-bridge and phase-shifted topologies
Fast switching with low Q_g/Q_gd ratio	Q_gd/Q_g = 51% - balances Miller effect immunity and switching speed for stable hard-switched operation
Low R_DS(on) × Q_g figure of merit	19.0 Ω·nC - improves trade-off between conduction and switching losses in 20–100 kHz power stages
RoHS-compliant Pb-free variant	IRF644PbF-BE3 meets JEDEC J-STD-609 Category 1 halogen-free requirements - suitable for environmentally regulated industrial shipments

Applications

Switch-Mode Power Supply	DC Motor Drive
Use Scenario: Primary-side switching in 100–300 W offline flyback and forward converters. IC Role / Device Role / Timing Role: Low-side N-channel MOSFET controlling energy transfer via transformer primary winding. Use Value: 250 V V_DS rating accommodates reflected output voltage plus leakage spike margin; 550 mJ E_AS handles transformer reset transients without snubber.	Use Scenario: H-bridge or half-bridge control of brushed DC motors in industrial actuators and HVAC dampers. IC Role / Device Role / Timing Role: High-current power switch enabling bidirectional torque control and regenerative braking. Use Value: 14 A continuous current and 56 A pulsed rating support peak stall currents; body diode recovery time <500 ns minimizes shoot-through risk during PWM commutation.
Uninterruptible Power Supply	LED Constant-Current Driver
Use Scenario: Inverter stage converting battery DC to 120/230 V AC output in line-interactive UPS systems. IC Role / Device Role / Timing Role: Output bridge switch operating in square-wave or modified sine-wave mode. Use Value: Repetitive avalanche capability ensures reliability during AC short-circuit events; TO-220AB package allows direct bolt-down heatsinking for >100 W thermal dissipation.	Use Scenario: Buck-regulated constant-current driver for high-brightness LED arrays in street lighting and signage. IC Role / Device Role / Timing Role: Synchronous rectifier or main PWM switch regulating average LED current. Use Value: 0.28 Ω R_DS(on) reduces conduction loss below 2 W at 8.5 A, improving system efficiency above 92%; 150 °C max T_J supports sealed outdoor enclosure operation.

Switch-Mode Power Supply

DC Motor Drive

Use Scenario: Primary-side switching in 100–300 W offline flyback and forward converters.

IC Role / Device Role / Timing Role: Low-side N-channel MOSFET controlling energy transfer via transformer primary winding.

Use Value: 250 V V_DS rating accommodates reflected output voltage plus leakage spike margin; 550 mJ E_AS handles transformer reset transients without snubber.

Use Scenario: H-bridge or half-bridge control of brushed DC motors in industrial actuators and HVAC dampers.

IC Role / Device Role / Timing Role: High-current power switch enabling bidirectional torque control and regenerative braking.

Use Value: 14 A continuous current and 56 A pulsed rating support peak stall currents; body diode recovery time <500 ns minimizes shoot-through risk during PWM commutation.

Uninterruptible Power Supply

LED Constant-Current Driver

Use Scenario: Inverter stage converting battery DC to 120/230 V AC output in line-interactive UPS systems.

IC Role / Device Role / Timing Role: Output bridge switch operating in square-wave or modified sine-wave mode.

Use Value: Repetitive avalanche capability ensures reliability during AC short-circuit events; TO-220AB package allows direct bolt-down heatsinking for >100 W thermal dissipation.

Use Scenario: Buck-regulated constant-current driver for high-brightness LED arrays in street lighting and signage.

IC Role / Device Role / Timing Role: Synchronous rectifier or main PWM switch regulating average LED current.

Use Value: 0.28 Ω R_DS(on) reduces conduction loss below 2 W at 8.5 A, improving system efficiency above 92%; 150 °C max T_J supports sealed outdoor enclosure operation.

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
STP20NM50FP	500 V V_DS, 0.24 Ω R_DS(on), 65 nC Q_g, TO-220FP (full-pack) package	Higher voltage rating but lower thermal performance (R_thJC = 1.4 °C/W); not avalanche-rated	Preferred where higher bus voltage margin is required and avalanche robustness is handled externally
IXTP12N25P	250 V V_DS, 0.25 Ω R_DS(on), 32 nC Q_g, TO-220 package, no avalanche rating	Lower gate charge enables faster switching but lacks UIS ruggedness and dV/dt immunity	Selected for high-frequency resonant converters where avalanche stress is absent and gate drive loss dominates

Compared with STP20NM50FP and IXTP12N25P, the IRF644 offers superior avalanche ruggedness and proven dV/dt immunity at the cost of higher Q_g - making it optimal for industrial motor drives and offline SMPS where reliability under transient overload is non-negotiable.

Availability

IRF644 is available at Aetrix Electronics and suitable for switch-mode power supplies, DC motor drives, uninterruptible power supplies, and LED constant-current drivers requiring stable component supply across multi-year production cycles.

Supply support for IRF644 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 IRF644 belongs to Vishay's third-generation power MOSFET family engineered for ruggedized switching in commercial-industrial power conversion - emphasizing avalanche survivability, thermal stability, and ease of paralleling.

FAQ

What is the maximum continuous drain current for IRF644 at 100 °C case temperature?

The IRF644 supports 8.5 A continuous drain current at T_C = 100 °C, as specified in the Absolute Maximum Ratings table. This derated value reflects thermal limitations of the TO-220AB package and must be validated against actual heatsink performance and ambient conditions in the final design. The IRF644 maintains safe operation only when junction temperature remains ≤150 °C.

Does IRF644 have avalanche capability, and how is it rated?

Yes, the IRF644 is repetitively avalanche rated: it supports 14 A repetitive avalanche current (I_AR) and 13 mJ repetitive avalanche energy (E_AR). Single-pulse avalanche energy is rated at 550 mJ. These values are measured under controlled unclamped inductive switching (UIS) conditions per Figure 12 and are valid only when pulse width and duty cycle remain within datasheet limits.

What is the gate threshold voltage range for IRF644, and how does it affect drive requirements?

The IRF644 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 full enhancement requires ≥10 V gate drive for low R_DS(on); logic-level compatibility is not guaranteed. The IRF644 is not a logic-level MOSFET, and using 5 V drive results in significantly higher on-resistance and conduction loss.

How does the body diode performance of IRF644 impact its use in synchronous rectification?

The IRF644 body diode has a forward voltage of 1.8 V at 14 A and reverse recovery time of 250–500 ns. While usable in non-synchronous flyback or buck topologies, its relatively slow recovery and high V_SD make it less efficient than dedicated Schottky or fast-recovery diodes in high-frequency synchronous rectification. The IRF644 is typically deployed as a main switch, not as a synchronous rectifier.

Is IRF644PbF-BE3 RoHS-compliant and halogen-free?

Yes, the IRF644PbF-BE3 variant is both lead (Pb)-free and halogen-free, meeting JEDEC J-STD-609 Category 1 requirements. It replaces legacy leaded versions while maintaining identical electrical and thermal specifications. The "BE3" suffix explicitly denotes Vishay's halogen-free packaging standard, verified per material composition analysis.

IRF644 Specifications

Product attributes: Attribute value

Manufacturer:: Vishay Siliconix

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 250 V

Current - Continuous Drain (Id) @ 25°C:: 14A (Tc)

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

Rds On (Max) @ Id, Vgs:: 280mOhm @ 8.4A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 68 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 1300 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 125W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220AB

IRF644 FAQ

1.How can I place an order for IRF644 through Aetrix?

Please submit a Request for Quotation (RFQ) for IRF644 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 IRF644 reliable?

The price and inventory of IRF644 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRF644 is usually 5 days.

3.What payment methods are accepted for IRF644?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRF644 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRF644?

IRF644 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRF644 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 IRF644?

For technical support, including IRF644 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRF644 requirements.

6.How does Aetrix verify that IRF644 is sourced from the original manufacturer or authorized distributors?

All IRF644 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 IRF644 meets industry standards.

7.What is the process for return or replacement of IRF644?

All IRF644 units undergo pre-shipment inspection (PSI). If there is an issue with IRF644, 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 IRF644 part is unused and in its original packaging.

Return procedure for IRF644:

1.Submit a request within 90 days.

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

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