Vishay Siliconix IRF634L

Overview

IRF634L from Vishay Siliconix is a 250 V, 8.1 A N-channel power MOSFET in TO-220AB package, optimized for hard-switched DC-DC converters and motor control circuits requiring rugged avalanche capability and fast switching. It delivers R_DS(on) = 0.45 Ω at V_GS = 10 V, Q_g = 41 nC, and E_AS = 300 mJ - enabling reliable operation in industrial power supplies and solenoid drivers.

For engineers reviewing the IRF634L datasheet, IRF634L pinout, IRF634L application, or IRF634L equivalent, key selection criteria include its repetitive avalanche rating (I_AR = 8.1 A), peak diode recovery dV/dt = 4.8 V/ns, body diode t_rr = 220–440 ns, and thermal resistance R_thJC = 1.7 °C/W - all critical for high-reliability 100–250 V switching designs.

Technical Context

This third-generation planar VDMOS device uses a robust silicon process with optimized gate oxide and drift region design to achieve simultaneous low R_DS(on), high dV/dt immunity, and controlled body diode recovery. Its dynamic dV/dt rating and unclamped inductive switching (UIS) capability are validated per JEDEC JESD24-11 under defined test conditions (V_DD = 50 V, L = 7.3 mH, I_AS = 8.1 A).

The MOSFET operates as a single-ended, enhancement-mode switch with gate threshold voltage V_GS(th) = 2.0–4.0 V and exhibits linear derating of 0.59 W/°C above T_C = 25 °C. Its internal source/drain inductances (L_S = 7.5 nH, L_D = 4.5 nH) are characterized for accurate switching waveform modeling in high-speed gate drive layouts.

Key Specifications

Pinout & Package

IRF634L is housed in a through-hole TO-220AB package with standard lead spacing and mounting hole for mechanical stability. The case is electrically connected to the drain terminal, requiring isolation when mounted to heatsinks.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP20NM50FP and IXTP12N25P, the IRF634L offers balanced trade-offs: it provides verified repetitive avalanche operation at 250 V with moderate R_DS(on) and gate charge, making it optimal for cost-sensitive industrial power stages where reliability under transient overload is mandatory.

Availability

IRF634L is available at Aetrix Electronics and suitable for industrial power supplies, motor drives, and solenoid control systems requiring stable component supply and long-term manufacturability.

Supply support for IRF634L 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 IRF634L belongs to Vishay's third-generation power MOSFET family, engineered for ruggedness and cost-effective performance in commercial-industrial switching applications up to 50 W dissipation.

FAQ

What is the maximum continuous drain current for IRF634L at 100 °C case temperature?

The IRF634L supports a continuous drain current of 5.1 A at T_C = 100 °C, as specified in the Absolute Maximum Ratings table. This derating reflects thermal limitations of the TO-220AB package and must be applied when ambient or heatsink conditions elevate case temperature beyond 25 °C. Designers should verify junction temperature using R_thJC = 1.7 °C/W and ensure T_J ≤ 150 °C under worst-case load and ambient conditions. The IRF634L data sheet confirms this value under standardized test conditions.

Does IRF634L have a built-in body diode, and what are its key parameters?

Yes, the IRF634L integrates a monolithic body diode with typical forward voltage V_SD = 2.0 V at I_S = 8.1 A and T_J = 25 °C. Its reverse recovery time t_rr ranges from 220 to 440 ns under I_F = 5.6 A and dI/dt = 100 A/μs. The diode also supports continuous source-drain current up to 8.1 A and pulsed current up to 32 A. These characteristics are measured and documented in the IRF634L datasheet's "Drain-Source Body Diode Characteristics" section.

Is IRF634L RoHS-compliant, and what does the 'L' suffix indicate?

The IRF634L is RoHS-compliant and lead (Pb)-free, consistent with Vishay's Pb-free product definition. The 'L' suffix denotes the lead-free version, distinct from the legacy IRF634 (non-RoHS). Vishay documents this compliance in the material categorization note and ordering information section of the IRF634L datasheet (Document Number: 91034), confirming adherence to Directive 2011/65/EU and related exemptions.

What is the gate-source threshold voltage range for IRF634L, and how does it affect drive requirements?

The IRF634L has a gate-source threshold voltage V_GS(th) ranging from 2.0 V to 4.0 V at I_D = 250 μA, indicating it is a standard-threshold MOSFET requiring ≥10 V gate drive for full enhancement. This ensures low R_DS(on) (0.45 Ω) but mandates compatible gate drivers capable of delivering sufficient voltage and current. The IRF634L's Q_g = 41 nC further defines the required gate drive strength to achieve target switching speeds without excessive losses.

Can IRF634L be used in parallel configurations, and what design considerations apply?

Yes, the IRF634L is designed for ease of paralleling, as stated in its features list. Key considerations include matched gate resistors (to balance turn-on timing), symmetrical PCB layout to minimize loop inductance, and thermal coupling to ensure uniform current sharing. Its positive R_DS(on) temperature coefficient promotes inherent current balancing. The IRF634L datasheet validates this capability through characterization of dynamic dV/dt immunity and thermal resistance, supporting stable multi-device operation in high-current power stages.