IRF644N N-Channel MOSFET 250V 14A TO-220AB Equivalent & Substitute Parts

Part Overview

The IRF644N is an N-Channel Metal Oxide Semiconductor Field Effect Transistor (MOSFET) rated for 250V drain-to-source voltage and 14A continuous drain current in a Through Hole TO-220AB package. This device is classified as obsolete, indicating that direct replacement with active production alternatives is necessary for new designs and ongoing procurement requirements. The IRF644N remains in inventory with 2,596 pieces available as new original stock; however, substitution with active product status components ensures long-term supply chain reliability and access to manufacturer support.

Substiute Parts

IRF644N

Vishay SiliconixIn Stock: 2694IRF644N Datasheet

Current PartRFQ

IRF644PBF

Vishay SiliconixIn Stock: 3380IRF644PBF Datasheet

MFR RecommendedRFQ

IRFB4229PBF

Infineon TechnologiesIn Stock: 8346IRFB4229PBF Datasheet

MFR RecommendedRFQ

STP17NF25

STMicroelectronicsIn Stock: 2172STP17NF25 Datasheet

MFR RecommendedRFQ

TK13E25D,S1X(S

Toshiba Semiconductor and StorageIn Stock: 962TK13E25D,S1X(S Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRF644N is determined by strict equivalence across the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

• Drain to Source Voltage (Vdss): 250V minimum
• Continuous Drain Current (Id): 14A minimum at 25°C
• Drive Voltage: 10V gate drive compatibility
• Gate Threshold Voltage (Vgs(th)): 4V maximum
• Mounting Type: Through Hole TO-220 package family
• FET Type: N-Channel Metal Oxide technology

Secondary Compatibility Factors:

• Maximum Gate Voltage (Vgs): ±20V or greater
• Operating Temperature Range: Minimum -55°C to 150°C
• Moisture Sensitivity Level: MSL 1 (Unlimited)

Substitute parts are grouped into two categories: Direct Equivalents (matching or exceeding all primary criteria with minimal parameter variance) and Enhanced Alternatives (exceeding primary criteria with improved electrical performance characteristics).

Parameter Comparison

Engineering Selection Recommendations

IRF644PBF (Vishay Siliconix) – Direct Equivalent

The IRF644PBF is the manufacturer-recommended direct substitute for the IRF644N. Both devices share identical base product designation and are manufactured by Vishay Siliconix. The IRF644PBF maintains 250V Vdss and 14A continuous drain current specifications. Key differences include ROHS3 compliance (versus non-compliant IRF644N), active product status, and slightly reduced maximum power dissipation (125W versus 150W). The IRF644PBF is supplied in Tube packaging and has 3,281 pieces in inventory. This substitute is suitable for applications where RoHS compliance is required and thermal design accommodates the 125W maximum power dissipation rating.

TK13E25D,S1X(S (Toshiba Semiconductor) – Direct Equivalent

The TK13E25D,S1X(S is a Toshiba N-Channel MOSFET rated for 250V Vdss with 13A continuous drain current, meeting the minimum current requirement. This device features ROHS3 compliance and active product status. Gate charge is significantly lower at 25 nC compared to 54 nC for the IRF644N, resulting in faster switching characteristics. Maximum power dissipation is 102W. Operating temperature range extends to 150°C maximum. This substitute is appropriate for applications prioritizing reduced gate charge and lower thermal dissipation requirements.

STP17NF25 (STMicroelectronics) – Direct Equivalent with Enhanced Current Rating

The STP17NF25 is an STMicroelectronics STripFET™ II series N-Channel MOSFET with 250V Vdss and 17A continuous drain current, exceeding the IRF644N current specification. This device demonstrates superior on-resistance performance at 165 mOhm (versus 240 mOhm for IRF644N), resulting in lower conduction losses. ROHS3 compliance and active product status are confirmed. Gate charge is 29.5 nC, providing improved switching efficiency. Maximum power dissipation is 90W. This substitute is suitable for applications where current margin and reduced conduction losses are beneficial, provided thermal design accommodates the 90W rating.

IRFB4229PBF (Infineon Technologies) – Enhanced Alternative

The IRFB4229PBF is an Infineon HEXFET® series N-Channel MOSFET with 250V Vdss and 46A continuous drain current, substantially exceeding the IRF644N current specification. This device features significantly improved on-resistance at 46 mOhm and maximum power dissipation of 330W, providing substantial thermal margin. ROHS3 compliance and active product status are confirmed. Operating temperature range extends to 175°C, matching the IRF644N upper limit. Gate charge is 110 nC, reflecting the higher current capability. This substitute is appropriate for applications requiring substantial current margin, reduced conduction losses, and enhanced thermal performance, with the understanding that the device is over-specified for 14A continuous current applications.

Frequently Asked Questions (FAQ)

Q: Can the IRF644PBF directly replace the IRF644N in existing designs?

A: Yes. The IRF644PBF maintains identical Vdss (250V) and Id (14A) specifications as the IRF644N. Both devices are manufactured by Vishay Siliconix and share the same base product number. The primary design consideration is the reduced maximum power dissipation (125W versus 150W). Thermal analysis of the existing design is required to confirm that the application does not exceed 125W continuous dissipation at the maximum operating junction temperature.

Q: What is the significance of RoHS compliance in selecting a substitute?

A: RoHS compliance indicates conformance to the Restriction of Hazardous Substances Directive. The IRF644N is RoHS non-compliant, while all substitute parts listed (IRF644PBF, TK13E25D,S1X(S, STP17NF25, and IRFB4229PBF) are ROHS3 compliant. For applications subject to RoHS requirements or customer specifications mandating RoHS compliance, selection of a compliant substitute is mandatory. Non-compliant devices may be restricted from procurement or use in regulated markets.

Q: Are all substitute parts pin-compatible with the IRF644N?

A: Yes. All substitute parts are supplied in Through Hole TO-220 package variants (TO-220AB or TO-220-3), which maintain identical pin configuration and mechanical footprint. Direct PCB mounting without layout modification is possible. Verify specific package designation (TO-220AB versus TO-220) with the component supplier to confirm exact mechanical compatibility with existing board designs.

Q: Which substitute offers the best on-resistance performance?

A: The IRFB4229PBF demonstrates the lowest on-resistance at 46 mOhm, compared to 240 mOhm for the IRF644N. The STP17NF25 offers the next best performance at 165 mOhm. Lower on-resistance reduces conduction losses and heat generation. Selection based on on-resistance alone requires verification that the application current levels and thermal design accommodate the device specifications.

Q: What is the impact of gate charge differences on circuit design?

A: Gate charge (Qg) determines the energy required to switch the MOSFET on and off. The IRF644N requires 54 nC at 10V gate drive. Substitute parts range from 25 nC (TK13E25D,S1X(S) to 110 nC (IRFB4229PBF). Lower gate charge reduces switching losses and allows faster switching frequencies. Higher gate charge increases driver power dissipation and may limit maximum switching frequency. Gate driver circuits must be verified to supply sufficient current for the selected device's gate charge specification.

Q: Can the IRFB4229PBF be used in applications designed for 14A continuous current?

A: Yes. The IRFB4229PBF is rated for 46A continuous drain current, substantially exceeding the 14A requirement. This provides current margin and reduced on-resistance, resulting in lower conduction losses. The device is electrically compatible with 14A applications. However, the higher gate charge (110 nC) and input capacitance (4560 pF) require verification that the gate driver circuit can supply the necessary switching current and energy. Over-specification may increase circuit complexity and cost without functional benefit.

Q: What are the temperature operating range implications for substitute selection?

A: The IRF644N operates from -55°C to 175°C junction temperature. Substitute parts operate within the following ranges: IRF644PBF (-55 to 150°C), TK13E25D,S1X(S (to 150°C), STP17NF25 (-55 to 150°C), and IRFB4229PBF (-40 to 175°C). For applications requiring operation at the full -55°C to 175°C range, the IRFB4229PBF is the only substitute maintaining the complete temperature specification. Other substitutes are limited to 150°C maximum, which may be acceptable depending on application thermal design and ambient conditions.

Q: Is inventory availability a factor in substitute selection?

A: Inventory levels are provided for reference: IRF644N (2,596 pieces), IRF644PBF (3,281 pieces), TK13E25D,S1X(S (856 pieces), STP17NF25 (2,117 pieces), and IRFB4229PBF (8,328 pieces). The IRFB4229PBF has the highest inventory level. However, inventory levels are subject to change and should not be the primary selection criterion. Substitute selection should be based on electrical compatibility, compliance requirements, and thermal design suitability. Inventory availability should be confirmed with the component supplier at the time of procurement.