IRF730AS N-Channel MOSFET 400V 5.5A Equivalent & Substitute Parts

Part Overview

The IRF730AS is an N-Channel MOSFET manufactured by Vishay Siliconix, rated for 400V drain-to-source voltage with 5.5A continuous drain current at 25°C. The device is packaged in TO-263 (D2PAK) surface mount configuration and dissipates up to 74W at case temperature. The IRF730AS is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. Substitute parts must maintain electrical compatibility across voltage, current, and thermal specifications while accommodating packaging and compliance requirements.

Substiute Parts

IRF730AS

Vishay SiliconixIn Stock: 1470IRF730AS Datasheet

Current PartRFQ

IRF730ASPBF

Vishay SiliconixIn Stock: 2504IRF730ASPBF Datasheet

DirectRFQ

STB11NK40ZT4

STMicroelectronicsIn Stock: 2395STB11NK40ZT4 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRF730AS is determined by strict equivalence across the following electrical and mechanical parameters:

Primary Substitution Criteria:

• Drain to Source Voltage (Vdss): Must equal or exceed 400V
• FET Type: Must be N-Channel
• Technology: Must be MOSFET (Metal Oxide)
• Mounting Type: Must be Surface Mount
• Package / Case: Must be compatible with TO-263-3 / D2PAK footprint

Secondary Compatibility Parameters:

• Current - Continuous Drain (Id): Substitute must support minimum 5.5A at 25°C
• Rds On (Max): Substitute must not exceed 1Ohm at specified Id and Vgs conditions
• Power Dissipation: Substitute must support minimum 74W at case temperature
• Operating Temperature Range: Must encompass -55°C to 150°C (TJ)
• Gate Charge (Qg): Provided for circuit design verification; not a substitution barrier

Substitutes are grouped into two categories: direct equivalents (identical electrical specifications) and functional equivalents (enhanced specifications within the same package and voltage class).

Parameter Comparison

Engineering Selection Recommendations

IRF730ASPBF (Vishay Siliconix): IRF730ASPBF is a direct electrical equivalent to IRF730AS with identical specifications across all key parameters: 400V Vdss, 5.5A continuous drain current, 1Ohm Rds On, and 74W power dissipation. The primary distinction is product status: IRF730ASPBF is active and ROHS3 compliant, whereas IRF730AS is obsolete and RoHS non-compliant. IRF730ASPBF maintains the same TO-263 (D2PAK) package footprint and thermal characteristics. Selection of IRF730ASPBF is appropriate for designs requiring direct replacement with modern compliance certifications and active manufacturing support.

STB11NK40ZT4 (STMicroelectronics): STB11NK40ZT4 is a functional equivalent within the 400V N-Channel MOSFET class, offering enhanced electrical performance relative to IRF730AS. The device provides 9A continuous drain current (versus 5.5A), 550mOhm Rds On (versus 1Ohm), and 110W power dissipation (versus 74W). STB11NK40ZT4 is packaged in D2PAK (TO-263-3) and operates across the same temperature range (-55°C to 150°C). Gate charge increases to 32 nC and input capacitance to 930 pF, reflecting the higher current capability. STB11NK40ZT4 is active and ROHS3 compliant. Selection is appropriate for designs where enhanced current handling and reduced on-resistance provide circuit performance benefits within the same package envelope.

Both substitute parts are compatible with the IRF730AS footprint and voltage specifications. Selection between IRF730ASPBF and STB11NK40ZT4 depends on circuit current requirements and thermal management strategy.

Frequently Asked Questions (FAQ)

Q: Can IRF730ASPBF be used as a direct replacement for IRF730AS? A: Yes. IRF730ASPBF is electrically identical to IRF730AS across all specified parameters: 400V Vdss, 5.5A Id, 1Ohm Rds On, and 74W power dissipation. Both devices use the same TO-263 (D2PAK) package. The primary difference is product status: IRF730ASPBF is active and ROHS3 compliant, while IRF730AS is obsolete.

Q: What are the differences between IRF730ASPBF and STB11NK40ZT4? A: Both devices share 400V Vdss and TO-263 (D2PAK) packaging. STB11NK40ZT4 offers higher current capability (9A versus 5.5A), lower on-resistance (550mOhm versus 1Ohm), and higher power dissipation (110W versus 74W). Gate charge and input capacitance are also higher in STB11NK40ZT4, reflecting its enhanced performance. Selection depends on circuit current and thermal requirements.

Q: Are the substitute parts compatible with the IRF730AS PCB footprint? A: Yes. Both IRF730ASPBF and STB11NK40ZT4 use the TO-263-3 (D2PAK) package with identical lead configuration and spacing. No PCB layout modifications are required for substitution.

Q: What is the significance of RoHS compliance for these parts? A: IRF730AS is RoHS non-compliant. IRF730ASPBF and STB11NK40ZT4 are both ROHS3 compliant. For applications subject to RoHS regulations or customer requirements, IRF730ASPBF or STB11NK40ZT4 must be selected.

Q: Can STB11NK40ZT4 be used in circuits designed for IRF730AS? A: STB11NK40ZT4 is functionally compatible with IRF730AS in circuits where the higher current rating (9A versus 5.5A) and lower on-resistance (550mOhm versus 1Ohm) do not create design conflicts. Gate charge and input capacitance are higher, which may affect switching speed and driver requirements. Circuit verification is necessary to confirm compatibility with specific gate drive and thermal management implementations.

Q: What is the operating temperature range for all three parts? A: All three parts operate across -55°C to 150°C (TJ). Temperature range is identical and does not differentiate substitution suitability.

Q: Are there inventory considerations for these substitute parts? A: IRF730AS has 1,385 pieces in stock (obsolete status). IRF730ASPBF has 2,428 pieces in stock (active). STB11NK40ZT4 has 2,285 pieces in stock (active). Both active substitutes have higher inventory availability than the obsolete original part.