IRF740S MOSFET N-Channel 400V 10A Equivalent & Substitute Parts

Part Overview

The IRF740S is an N-Channel MOSFET manufactured by Vishay Siliconix, rated for 400V drain-to-source voltage with 10A continuous drain current. The device is housed in a TO-263 (D2PAK) surface mount package and is designed for high-voltage switching applications. The IRF740S is classified as obsolete, necessitating identification of equivalent and substitute components for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility across voltage ratings, current handling, and thermal characteristics while meeting modern compliance standards.

Substiute Parts

IRF740S

Vishay SiliconixIn Stock: 13642IRF740S Datasheet

Current PartRFQ

IRF740SPBF

Vishay SiliconixIn Stock: 2616IRF740SPBF Datasheet

DirectRFQ

STB11NK40ZT4

STMicroelectronicsIn Stock: 2395STB11NK40ZT4 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRF740S is determined by strict equivalence across the following critical electrical and mechanical parameters:

Mandatory Equivalence Criteria:

• Drain to Source Voltage (Vdss): 400V minimum
• Continuous Drain Current (Id): 10A or greater at 25°C
• Drive Voltage (Max Rds On): 10V
• Package Type: TO-263 (D2PAK) surface mount
• Operating Temperature Range: -55°C to 150°C minimum
• Moisture Sensitivity Level: 1 (Unlimited)

Acceptable Variation Parameters:

• Rds On (Max): Equal or lower resistance values
• Gate Charge (Qg): Lower or equal values preferred for reduced switching losses
• Input Capacitance (Ciss): Lower or equal values preferred for faster switching
• Vgs (Max): Equal or greater gate voltage rating
• Power Dissipation: Equal or greater thermal capability

Substitute parts must satisfy all mandatory criteria. Variations in acceptable parameters do not disqualify a part from substitution provided the mandatory specifications are met or exceeded.

Parameter Comparison

Engineering Selection Recommendations

IRF740SPBF (Vishay Siliconix)

The IRF740SPBF is a direct equivalent to the IRF740S with identical electrical specifications. Both devices are manufactured by Vishay Siliconix and share the same base product number (IRF740). The IRF740SPBF maintains 400V Vdss, 10A continuous drain current, and 550 mOhm Rds On characteristics. The primary distinction is product status: IRF740SPBF is active and RoHS3 compliant, whereas the IRF740S is obsolete and RoHS non-compliant. The IRF740SPBF is supplied in tube packaging and is suitable for direct replacement in applications requiring modern compliance standards.

STB11NK40ZT4 (STMicroelectronics)

The STB11NK40ZT4 is a functional substitute manufactured by STMicroelectronics using SuperMESH™ technology. This device meets the mandatory substitution criteria with 400V Vdss and surface mount D2PAK packaging. The continuous drain current is rated at 9A, which is 1A lower than the IRF740S specification. The STB11NK40ZT4 offers performance advantages including reduced gate charge (32 nC versus 63 nC) and lower input capacitance (930 pF versus 1400 pF), resulting in faster switching characteristics. Power dissipation is rated at 110W (Tc), which is lower than the IRF740S at 125W (Tc). The STB11NK40ZT4 is active, RoHS3 compliant, and supplied in cut tape and digi-reel packaging.

Selection Basis:

For applications requiring exact electrical equivalence and maximum current handling, the IRF740SPBF is the appropriate selection. For applications where the 9A continuous drain current is sufficient and improved switching performance is beneficial, the STB11NK40ZT4 provides an alternative with enhanced characteristics. Both substitute parts are active products with current compliance certifications, addressing the obsolescence of the IRF740S.

Frequently Asked Questions (FAQ)

Q: Can the IRF740SPBF be used as a direct replacement for the IRF740S?

A: Yes. The IRF740SPBF is electrically and mechanically identical to the IRF740S. Both devices share the same base product number, voltage rating (400V), current rating (10A), on-resistance (550 mOhm @ 6A, 10V), and package type (TO-263 D2PAK). The IRF740SPBF is the active production equivalent and is RoHS3 compliant.

Q: What is the primary difference between the IRF740S and STB11NK40ZT4?

A: The primary difference is continuous drain current: the IRF740S is rated for 10A while the STB11NK40ZT4 is rated for 9A. Both devices maintain 400V Vdss and 550 mOhm Rds On at 10V drive voltage. The STB11NK40ZT4 features lower gate charge (32 nC versus 63 nC) and lower input capacitance (930 pF versus 1400 pF), enabling faster switching operation. Applications requiring the full 10A rating must use the IRF740SPBF or IRF740S.

Q: Are all three parts compatible with the same PCB layout?

A: Yes. All three parts use the TO-263 (D2PAK) surface mount package with identical pinout and footprint. PCB layout modifications are not required for substitution among these devices.

Q: What is the impact of the lower gate charge in the STB11NK40ZT4?

A: Lower gate charge (32 nC versus 63 nC) reduces the energy required to switch the device and decreases switching time. This results in lower switching losses and improved efficiency in high-frequency applications. The trade-off is a 1A reduction in continuous drain current rating.

Q: Are there compliance differences between the substitute parts?

A: Yes. The IRF740S is RoHS non-compliant and REACH unaffected. The IRF740SPBF is RoHS3 compliant and REACH affected. The STB11NK40ZT4 is RoHS3 compliant and REACH unaffected. Applications subject to RoHS3 requirements must use either the IRF740SPBF or STB11NK40ZT4.

Q: Can the STB11NK40ZT4 be used in applications designed for 10A continuous current?

A: The STB11NK40ZT4 is rated for 9A continuous drain current. Applications requiring sustained 10A operation must use the IRF740SPBF or IRF740S. The STB11NK40ZT4 may be suitable for applications with peak current requirements of 10A provided the continuous average current does not exceed 9A.

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

A: All three devices operate across the same temperature range: -55°C to 150°C (TJ). Thermal management and junction temperature calculations remain consistent across all three parts.

Q: Are there packaging differences that affect component handling?

A: The IRF740S is supplied in standard packaging (status obsolete). The IRF740SPBF is supplied in tube packaging. The STB11NK40ZT4 is supplied in cut tape and digi-reel packaging. All three devices have MSL rating of 1 (Unlimited), indicating no moisture sensitivity restrictions during storage and handling.