FDP18N20F Equivalent & Substitute Parts

Part Overview

The FDP18N20F is an N-Channel MOSFET manufactured by onsemi, rated for 200V drain-to-source voltage with 18A continuous drain current at 25°C. This device is packaged in a Through Hole TO-220-3 configuration and is part of the UniFET™ series. The FDP18N20F is classified as Obsolete, making identification of equivalent and substitute parts essential for ongoing design support and component procurement.

Substiute Parts

FDP18N20F

onsemiIn Stock: 22792FDP18N20F Datasheet

Current PartRFQ

FDPF18N20FT

onsemiIn Stock: 15320FDPF18N20FT Datasheet

MFR RecommendedRFQ

IRF640NPBF

Infineon TechnologiesIn Stock: 85421IRF640NPBF Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDP18N20F is determined by strict equivalence across the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

• Drain to Source Voltage (Vdss): 200V
• Continuous Drain Current (Id) @ 25°C: 18A (Tc)
• Drive Voltage (Max Rds On): 10V
• Gate Threshold Voltage (Vgs(th)): 5V @ 250µA
• Maximum Gate Voltage (Vgs): ±30V
• Operating Temperature Range: -55°C to 150°C minimum
• Mounting Type: Through Hole
• Package Category: TO-220 family

Secondary Compatibility Parameters:

• Gate Charge (Qg): 26 nC @ 10V
• Input Capacitance (Ciss): 1180 pF @ 25V
• RoHS3 Compliance

The substitute parts identified maintain electrical equivalence across voltage and current ratings while accommodating minor variations in thermal performance and package configuration within the TO-220 family. Substitutes are grouped by manufacturer recommendation status and product lifecycle status.

Parameter Comparison

Engineering Selection Recommendations

FDPF18N20FT (onsemi) - Recommended Substitute

The FDPF18N20FT is the manufacturer-recommended equivalent for the obsolete FDP18N20F. Both devices are manufactured by onsemi and share identical electrical specifications across all critical parameters: 200V Vdss, 18A continuous drain current, 10V drive voltage, 5V gate threshold voltage, and ±30V maximum gate voltage. The FDPF18N20FT maintains the same gate charge (26 nC @ 10V) and input capacitance (1180 pF @ 25V). The primary difference is packaging: FDPF18N20FT uses TO-220F-3 (full pack) versus the original TO-220-3 configuration. Both devices operate across the -55°C to 150°C temperature range and maintain ROHS3 compliance. The FDPF18N20FT is currently in Active product status, ensuring long-term availability and supply chain continuity. Power dissipation differs (41W versus 100W), reflecting thermal management differences between package variants.

IRF640NPBF (Infineon Technologies) - Direct Substitute

The IRF640NPBF is a direct electrical substitute meeting the core voltage and current requirements: 200V Vdss and 18A continuous drain current at 10V drive voltage. This device is manufactured by Infineon Technologies under the HEXFET® series. Electrical parameters remain compatible across Vdss, Id, and drive voltage specifications. Notable differences include: gate threshold voltage of 4V (versus 5V), higher gate charge of 67 nC @ 10V (versus 26 nC), maximum gate voltage of ±20V (versus ±30V), and extended operating temperature range to 175°C (versus 150°C). The IRF640NPBF is packaged in TO-220AB configuration and carries ROHS3 compliance. Product status is classified as Not For New Designs, indicating this device is suitable for replacement applications but not recommended for new circuit development. Power dissipation is rated at 150W (Tc), providing higher thermal capacity than the original FDP18N20F.

Selection Basis:

For direct replacement of the obsolete FDP18N20F in existing designs, the FDPF18N20FT is the primary choice due to manufacturer continuity, identical electrical specifications, and Active product status. The IRF640NPBF serves as an alternative when cross-manufacturer sourcing is required or when higher thermal performance is beneficial, with the understanding that gate charge and maximum gate voltage specifications differ and must be evaluated within the specific circuit context.

Frequently Asked Questions (FAQ)

Q: Can the FDPF18N20FT directly replace the FDP18N20F without circuit modification?

A: The FDPF18N20FT is electrically equivalent to the FDP18N20F across all critical parameters: Vdss (200V), Id (18A), drive voltage (10V), gate threshold voltage (5V), and gate charge (26 nC @ 10V). The primary difference is package configuration (TO-220F-3 versus TO-220-3). Both are Through Hole devices with compatible pinouts. Mechanical fit and thermal management characteristics may differ due to package variant; verify PCB footprint compatibility and heatsink interface requirements for your specific application.

Q: What are the key electrical differences between the FDP18N20F and IRF640NPBF?

A: Both devices share identical Vdss (200V) and Id (18A) ratings at 10V drive voltage. Differences include: gate threshold voltage (5V versus 4V), gate charge (26 nC versus 67 nC @ 10V), maximum gate voltage (±30V versus ±20V), and operating temperature range (-55°C to 150°C versus -55°C to 175°C). The IRF640NPBF exhibits higher gate charge, which may affect switching speed and gate drive circuit requirements. Maximum gate voltage limitation (±20V) must be verified against your gate drive circuit specifications.

Q: Why does the FDPF18N20FT have lower power dissipation (41W) than the FDP18N20F (100W)?

A: Power dissipation ratings reflect thermal performance under specified test conditions and package thermal characteristics. The TO-220F-3 package (FDPF18N20FT) and TO-220-3 package (FDP18N20F) have different thermal resistance values. Lower power dissipation rating does not indicate reduced electrical capability; both devices handle 18A continuous drain current identically. Thermal performance depends on heatsink design, mounting configuration, and ambient conditions. Consult device datasheets for thermal resistance (θJA and θJC) specifications relevant to your thermal management design.

Q: Is the IRF640NPBF suitable for new circuit designs?

A: The IRF640NPBF carries a product status of Not For New Designs. This classification indicates the device is available for replacement and repair applications but is not recommended for new circuit development. For new designs, the FDPF18N20FT (Active status) is the preferred choice. If cross-manufacturer sourcing is required for new designs, alternative devices with Active product status should be evaluated.

Q: Are all three devices RoHS3 compliant?

A: Yes. The FDP18N20F, FDPF18N20FT, and IRF640NPBF are all ROHS3 compliant, meeting environmental and hazardous substance restrictions for electronic components.

Q: What is the significance of the different maximum gate voltages (±30V versus ±20V)?

A: Maximum gate voltage (Vgs Max) defines the safe operating range for gate drive signals. The FDP18N20F and FDPF18N20FT support ±30V gate voltage, while the IRF640NPBF is limited to ±20V. If your gate drive circuit produces voltage levels exceeding ±20V, the IRF640NPBF is not suitable without gate voltage clamping or limiting circuitry. Verify your gate drive specifications against the selected device's Vgs Max rating.

Q: Can I use the IRF640NPBF in a circuit designed for the FDP18N20F?

A: Electrical substitution is possible due to matching Vdss, Id, and drive voltage specifications. However, circuit-level evaluation is required for: gate charge differences (67 nC versus 26 nC), which affect switching transients and gate drive current requirements; gate threshold voltage difference (4V versus 5V), which may affect switching threshold timing; and maximum gate voltage limitation (±20V versus ±30V), which must be compatible with your gate drive circuit. Thermal performance differences must also be assessed based on your heatsink and thermal management design.