IRF720 N-Channel MOSFET 400V 3.3A Equivalent & Substitute Parts

Part Overview

The IRF720 is an N-Channel Metal Oxide Semiconductor Field Effect Transistor (MOSFET) rated for 400V drain-to-source voltage with a continuous drain current of 3.3A at 25°C. The device is housed in a Through Hole TO-220AB package and dissipates up to 50W. The IRF720 is classified as obsolete, necessitating identification of active equivalent and substitute components for new designs and ongoing production requirements. Substitute parts must maintain electrical and mechanical compatibility within the specified parameter ranges.

Substiute Parts

IRF720

Vishay SiliconixIn Stock: 33036IRF720 Datasheet

Current PartRFQ

IRF720PBF

Vishay SiliconixIn Stock: 7601IRF720PBF Datasheet

DirectRFQ

STP7NK40Z

STMicroelectronicsIn Stock: 8094STP7NK40Z Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the IRF720 are classified based on electrical parameter compatibility and physical packaging equivalence. The primary substitution criteria are:

Electrical Compatibility Parameters:

• Drain to Source Voltage (Vdss): Must equal or exceed 400V
• Continuous Drain Current (Id): Must meet or exceed 3.3A at 25°C
• Drive Voltage: Must support 10V gate drive
• On-State Resistance (Rds On): Must not exceed specified maximum values at rated conditions
• Power Dissipation: Must support thermal requirements
• Operating Temperature Range: Must encompass -55°C to 150°C

Mechanical Compatibility Parameters:

• Mounting Type: Through Hole
• Package / Case: TO-220-3 footprint

Compliance Parameters:

• RoHS Status: Preference for RoHS3 Compliant devices
• Moisture Sensitivity Level: MSL 1 (Unlimited)

The IRF720PBF is a direct equivalent manufactured by Vishay Siliconix with identical electrical specifications and active product status. The STP7NK40Z is a manufacturer-recommended substitute from STMicroelectronics that exceeds the IRF720 specifications in drain current (5.4A vs. 3.3A) and power dissipation (70W vs. 50W) while maintaining voltage and temperature compatibility.

Parameter Comparison

Engineering Selection Recommendations

IRF720PBF (Vishay Siliconix): This part is the direct electrical and mechanical equivalent of the IRF720. It maintains identical specifications for Vdss, Id, Rds On, and power dissipation. The IRF720PBF carries active product status and ROHS3 compliance, making it the primary choice for direct replacement in applications currently using the obsolete IRF720. The part is available in Tube packaging and provides continuity for existing designs without circuit modification.

STP7NK40Z (STMicroelectronics): This part is a manufacturer-recommended substitute that exceeds IRF720 performance specifications. The STP7NK40Z provides higher continuous drain current (5.4A vs. 3.3A) and increased power dissipation capability (70W vs. 50W) while maintaining the same 400V Vdss rating and operating temperature range. The lower on-state resistance (1.0 Ohm @ 2.7A, 10V vs. 1.8 Ohm @ 2A, 10V) provides improved efficiency. The STP7NK40Z is ROHS3 compliant and carries active product status. This part is suitable for applications where the IRF720 specifications are met or exceeded, and where the enhanced performance characteristics provide design margin or thermal headroom.

Both substitute parts maintain TO-220-3 package compatibility and MSL 1 moisture sensitivity rating. Selection between IRF720PBF and STP7NK40Z depends on application requirements: use IRF720PBF for direct replacement with identical specifications; use STP7NK40Z where enhanced current handling and thermal performance are beneficial.

Frequently Asked Questions (FAQ)

Q: Can the IRF720PBF be used as a direct replacement for the IRF720?

A: Yes. The IRF720PBF is electrically and mechanically identical to the IRF720. Both devices share the same Vdss (400V), Id (3.3A), Rds On (1.8 Ohm @ 2A, 10V), power dissipation (50W), and TO-220-3 package. The IRF720PBF is active and ROHS3 compliant, making it suitable for direct substitution without circuit modification.

Q: What are the key differences between the IRF720 and STP7NK40Z?

A: The STP7NK40Z exceeds IRF720 specifications in two areas: continuous drain current (5.4A vs. 3.3A) and power dissipation (70W vs. 50W). The STP7NK40Z also features lower on-state resistance (1.0 Ohm @ 2.7A, 10V). Both devices maintain 400V Vdss, 10V drive voltage, and -55°C to 150°C operating temperature range. The STP7NK40Z is manufactured by STMicroelectronics and carries active product status with ROHS3 compliance.

Q: Are the IRF720PBF and STP7NK40Z pin-compatible?

A: Yes. Both substitute parts use the TO-220-3 package with identical pin configuration and footprint as the IRF720. Both are Through Hole mounted devices suitable for the same PCB layouts.

Q: Which substitute part should be selected for new designs?

A: For new designs, the IRF720PBF is recommended if the application requires exactly 3.3A continuous drain current and 50W power dissipation. The STP7NK40Z is recommended if the application can benefit from higher current capability (5.4A) or increased thermal headroom (70W), or if design margin is desired. Both parts are active and ROHS3 compliant.

Q: Are there any compliance differences between the substitute parts?

A: Both IRF720PBF and STP7NK40Z are ROHS3 compliant and carry MSL 1 (Unlimited) moisture sensitivity rating. The original IRF720 is RoHS non-compliant. For applications requiring RoHS compliance, either substitute part is acceptable.

Q: What is the operating temperature range for all three parts?

A: All three parts (IRF720, IRF720PBF, and STP7NK40Z) operate across the same temperature range: -55°C to 150°C (TJ).

Q: Can the STP7NK40Z be used in applications designed for the IRF720?

A: Yes. The STP7NK40Z meets or exceeds all IRF720 electrical specifications. The higher current rating (5.4A vs. 3.3A) and power dissipation (70W vs. 50W) ensure compatibility with applications designed for the IRF720. The identical 400V Vdss, 10V drive voltage, and TO-220-3 package provide mechanical and electrical compatibility.