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

Vishay Siliconix IRF634NPBF

Name: IRF634NPBF
Brand: Vishay Siliconix
SKU: IRF634NPBF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRF634NPBF

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

Package:: TO-220-3

Datasheet:: IRF634NPBF.pdf

Description:: MOSFET N-CH 250V 8A TO220AB

Quantity:: RFQ Add To RFQ list

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Product details

Overview

IRF634NPBF from Vishay Siliconix is a 250 V, 8.0 A N-channel power MOSFET in TO-220 package with 0.435 Ω R_DS(on) at V_GS = 10 V, 34 nC total gate charge, and 175 °C maximum junction temperature-designed for high-efficiency switch-mode power supplies, motor drives, and DC-DC converters.

For engineers reviewing the IRF634NPBF datasheet, IRF634NPBF pinout, IRF634NPBF application, or IRF634NPBF equivalent, this page delivers verified electrical parameters, thermal ratings, avalanche capability, switching timing data, and real-world design context for reliable high-voltage power switching implementation.

Technical Context

The IRF634NPBF employs fifth-generation silicon process technology to achieve low on-resistance per die area while maintaining ruggedness against repetitive and single-pulse avalanche stress. Its dynamic dV/dt rating of 7.3 V/ns and fully rated avalanche energy (E_AS = 110 mJ) support robust operation in inductive switching environments.

Designed for hard-switched topologies, it features fast turn-on delay (8.4 ns), rise time (16 ns), and fall time (15 ns) under standardized test conditions (V_DD = 125 V, I_D = 4.8 A, R_G = 1.3 Ω), with gate drive compatibility requiring only 10 V for full enhancement and minimal 100 nA gate leakage.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	250 V - supports primary-side switching in offline SMPS up to 230 VAC mains with safety margin
R_DS(on)	0.435 Ω @ V_GS = 10 V - enables ≤1.7 W conduction loss at 8 A continuous drain current
Q_g	34 nC - determines gate driver power requirement and switching loss trade-off in high-frequency designs
E_AS	110 mJ - allows safe unclamped inductive switching without external snubbers in relay/motor control
T_J(max)	+175 °C - permits operation in sealed enclosures or high-ambient industrial environments
P_D	88 W @ T_C = 25 °C - defines heatsink sizing baseline for TO-220 mounting at case temperature
dV/dt	7.3 V/ns - ensures immunity to false triggering during high-slew-rate voltage transients

Pinout & Package

IRF634NPBF uses the industry-standard TO-220 through-hole package with isolated tab (drain-connected), offering low thermal resistance (R_thJC = 1.7 °C/W) and mechanical stability for power dissipation up to 88 W when properly heatsinked.

Pin/Terminal	Circuit Role	Design Meaning
Drain (Tab)	Main current path output terminal	Electrically connected to metal tab; requires insulating washer if mounted to grounded heatsink
Gate	Control input for channel conduction	High-impedance MOS gate; driven by 10 V logic-level signal with <100 nA leakage
Source	Reference node for gate drive and current return	Serves as common reference for gate-source voltage and load current return path

Key Features

Feature	Design Value
Fully avalanche rated	Withstands 110 mJ single-pulse and 8.8 mJ repetitive avalanche energy without failure
Dynamic dV/dt immunity	7.3 V/ns rating prevents spurious turn-on during fast voltage transients in bridge circuits
175 °C operating temperature	Enables use in automotive under-hood or industrial motor control without derating at high ambient
Low Q_gd/Q_g ratio	16/34 ≈ 47 % - improves hard-switching efficiency and reduces Miller-induced oscillation risk
Lead (Pb)-free construction	RoHS-compliant finish with SnAgCu plating; compatible with standard reflow and wave soldering

Applications

Switch-Mode Power Supply	Motor Drive
Use Scenario: Primary-side switching transistor in 60–150 W offline flyback or forward converters. IC Role / Device Role / Timing Role: High-voltage power switch controlling energy transfer from AC line to transformer primary. Use Value: 250 V V_DS and 110 mJ E_AS eliminate need for clamping circuits during transformer reset.	Use Scenario: Half-bridge high-side switch in 24–48 V brushed DC motor controllers. IC Role / Device Role / Timing Role: Fast-turning N-channel switch enabling PWM speed regulation with minimal dead-time loss. Use Value: 8.4 ns t_d(on) and 15 ns t_f support >100 kHz PWM frequencies while maintaining efficiency.
DC-DC Converter	Industrial Relay Driver
Use Scenario: Synchronous rectifier or main switch in isolated 48 V input telecom DC-DC modules. IC Role / Device Role / Timing Role: High-efficiency power switch handling continuous 8 A output current with low R_DS(on). Use Value: 0.435 Ω R_DS(on) limits conduction loss to ≤2.8 W at full load, reducing thermal management burden.	Use Scenario: Solid-state replacement for electromechanical relays in programmable logic controller (PLC) output modules. IC Role / Device Role / Timing Role: Robust load switch isolating 24 V DC field devices with overcurrent and avalanche protection. Use Value: +175 °C T_J(max) and 32 A I_DM support surge-tolerant operation during solenoid coil de-energization.

Switch-Mode Power Supply

Motor Drive

Use Scenario: Primary-side switching transistor in 60–150 W offline flyback or forward converters.

IC Role / Device Role / Timing Role: High-voltage power switch controlling energy transfer from AC line to transformer primary.

Use Value: 250 V V_DS and 110 mJ E_AS eliminate need for clamping circuits during transformer reset.

Use Scenario: Half-bridge high-side switch in 24–48 V brushed DC motor controllers.

IC Role / Device Role / Timing Role: Fast-turning N-channel switch enabling PWM speed regulation with minimal dead-time loss.

Use Value: 8.4 ns t_d(on) and 15 ns t_f support >100 kHz PWM frequencies while maintaining efficiency.

DC-DC Converter

Industrial Relay Driver

Use Scenario: Synchronous rectifier or main switch in isolated 48 V input telecom DC-DC modules.

IC Role / Device Role / Timing Role: High-efficiency power switch handling continuous 8 A output current with low R_DS(on).

Use Value: 0.435 Ω R_DS(on) limits conduction loss to ≤2.8 W at full load, reducing thermal management burden.

Use Scenario: Solid-state replacement for electromechanical relays in programmable logic controller (PLC) output modules.

IC Role / Device Role / Timing Role: Robust load switch isolating 24 V DC field devices with overcurrent and avalanche protection.

Use Value: +175 °C T_J(max) and 32 A I_DM support surge-tolerant operation during solenoid coil de-energization.

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, 20 A I_D, 0.23 Ω R_DS(on), TO-220FP package with insulated tab	Higher voltage rating and current capacity; better suited for 400 V bus applications	Select when higher blocking voltage or lower on-resistance is required, accepting larger footprint and higher gate charge
IXTP12N25P	250 V V_DS, 12 A I_D, 0.22 Ω R_DS(on), TO-220 package, no lead-free option listed	Lower R_DS(on) and higher current rating but lacks documented avalanche rating and RoHS-compliant variant	Prefer for higher-current 250 V designs where avalanche robustness is secondary and Pb-free compliance is not mandated

Compared with STP20NM50FP and IXTP12N25P, the IRF634NPBF offers balanced 250 V/8 A capability with verified avalanche performance, RoHS compliance, and proven thermal reliability in TO-220-making it optimal for cost-sensitive, thermally constrained 60–150 W power stages.

Availability

IRF634NPBF is available at Aetrix Electronics and suitable for switch-mode power supplies, motor drives, and industrial relay drivers requiring stable component supply and long-term manufacturing continuity.

Supply support for IRF634NPBF 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 reliability, ruggedness, and high-voltage performance.

The IRF634NPBF belongs to Vishay's fifth-generation Power MOSFET product line, engineered for high-efficiency, high-reliability switching in industrial and commercial power conversion systems.

FAQ

What is the maximum continuous drain current for the IRF634NPBF at 100 °C case temperature?

The IRF634NPBF supports 5.6 A continuous drain current at T_C = 100 °C, as specified in its absolute maximum ratings table. This derating reflects thermal limitations of the TO-220 package and must be applied when heatsink temperature exceeds 25 °C. Designers should verify junction temperature using R_thJC = 1.7 °C/W and ensure T_J remains ≤175 °C. The IRF634NPBF maintains stable R_DS(on) across this range due to its positive temperature coefficient.

Does the IRF634NPBF have a built-in body diode, and what are its key characteristics?

Yes, the IRF634NPBF integrates a parasitic body diode with 1.3 V forward voltage at 4.8 A and 25 °C, 130–200 ns reverse recovery time, and 650–980 nC reverse recovery charge. This diode enables freewheeling in inductive loads but is not optimized for synchronous rectification. Its trr and Qrr values indicate moderate recovery behavior-acceptable for flyback snubberless operation but not recommended for high-frequency ZVS topologies. The IRF634NPBF body diode is rated for 8.0 A continuous and 32 A pulsed current.

Can the IRF634NPBF be used in avalanche mode, and what energy level is supported?

Yes, the IRF634NPBF is fully avalanche rated with 110 mJ single-pulse avalanche energy (E_AS) and 8.8 mJ repetitive avalanche energy (E_AR). These values are measured under standardized conditions (L = 9.5 mH, I_AS = 4.8 A, V_GS = 10 V). Operation in unclamped inductive switching requires adherence to the SOA curve and thermal limits. The IRF634NPBF's avalanche capability eliminates need for external clamps in many relay and solenoid drive applications.

What is the gate threshold voltage range for the IRF634NPBF, and how does it affect drive requirements?

The IRF634NPBF has a gate threshold voltage (V_GS(th)) range of 2.0 V to 4.0 V at I_D = 250 µA. This confirms standard-level-not logic-level-drive requirements: full enhancement occurs at V_GS = 10 V, delivering 0.435 Ω R_DS(on). Driving below 6 V risks incomplete turn-on and excessive conduction loss. The IRF634NPBF's 100 nA gate leakage ensures minimal drive current demand, simplifying gate driver selection.

Is the IRF634NPBF RoHS compliant, and what does the 'PbF' suffix signify?

Yes, the IRF634NPBF is RoHS compliant, as confirmed by Vishay's documentation and the 'PbF' (lead-free) suffix in its part number. It uses SnAgCu termination plating and meets EU Directive 2011/65/EU requirements. The 'PbF' designation distinguishes it from the legacy SnPb version (IRF634N). The IRF634NPBF is qualified for standard reflow profiles and supports both wave and selective soldering processes without compromising reliability.

IRF634NPBF 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:: 8A (Tc)

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

Rds On (Max) @ Id, Vgs:: 435mOhm @ 4.8A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 34 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 620 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 3.8W (Ta), 88W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220AB

IRF634NPBF FAQ

1.How can I place an order for IRF634NPBF through Aetrix?

Please submit a Request for Quotation (RFQ) for IRF634NPBF 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 IRF634NPBF reliable?

The price and inventory of IRF634NPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRF634NPBF is usually 5 days.

3.What payment methods are accepted for IRF634NPBF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRF634NPBF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRF634NPBF?

IRF634NPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRF634NPBF 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 IRF634NPBF?

For technical support, including IRF634NPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRF634NPBF requirements.

6.How does Aetrix verify that IRF634NPBF is sourced from the original manufacturer or authorized distributors?

All IRF634NPBF 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 IRF634NPBF meets industry standards.

7.What is the process for return or replacement of IRF634NPBF?

All IRF634NPBF units undergo pre-shipment inspection (PSI). If there is an issue with IRF634NPBF, 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 IRF634NPBF part is unused and in its original packaging.

Return procedure for IRF634NPBF:

1.Submit a request within 90 days.

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

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