IRF730STRL Equivalent & Substitute Parts

Part Overview

The IRF730STRL is an N-Channel MOSFET manufactured by Vishay Siliconix, rated for 400V drain-to-source voltage with 5.5A continuous drain current in a surface mount TO-263 (D2PAK) package. This device is classified as obsolete, which necessitates identification of equivalent and substitute components for ongoing design support and procurement.

The IRF730STRL serves in applications requiring moderate voltage and current switching capabilities with the compact D2PAK form factor. Due to its obsolete status, active alternatives with matching or superior electrical characteristics are required for new designs and production continuity.

Substiute Parts

IRF730STRL

Vishay SiliconixIn Stock: 734IRF730STRL Datasheet

Current PartRFQ

IRF730STRLPBF

Vishay SiliconixIn Stock: 851IRF730STRLPBF Datasheet

Parametric EquivalentRFQ

IRF730STRR

Vishay SiliconixIn Stock: 688IRF730STRR Datasheet

Parametric EquivalentRFQ

IRF730STRRPBF

Vishay SiliconixIn Stock: 2961IRF730STRRPBF Datasheet

Parametric EquivalentRFQ

STB11NK40ZT4

STMicroelectronicsIn Stock: 2395STB11NK40ZT4 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRF730STRL is determined by electrical and mechanical compatibility across the following critical parameters:

Electrical Compatibility Criteria:

• Drain-to-Source Voltage (Vdss): Must equal or exceed 400V
• Continuous Drain Current (Id): Must equal or exceed 5.5A at 25°C
• On-State Resistance (Rds On): Must not exceed 1 Ohm at specified conditions
• Gate Threshold Voltage (Vgs(th)): Must be compatible with 4V specification
• Gate Charge (Qg): Lower values indicate faster switching; 38 nC is the reference
• Input Capacitance (Ciss): Lower values reduce gate drive requirements; 700 pF is the reference
• Operating Temperature Range: Must support -55°C to 150°C (TJ)
• Gate Voltage (Vgs): Must support ±20V or greater

Mechanical Compatibility Criteria:

• Package Type: TO-263 (D2PAK) surface mount configuration
• Pin configuration: 2 leads plus tab

Substitutes are grouped into two categories:

1. Parametric Equivalents (Vishay Siliconix IRF730 Series): Identical electrical specifications with variations in packaging format (bulk vs. tape & reel) and RoHS compliance status. These parts are direct functional replacements.

2. Manufacturer Recommended Substitute (STMicroelectronics STB11NK40ZT4): Enhanced performance characteristics including higher continuous drain current (9A vs. 5.5A), lower on-state resistance (550mOhm vs. 1 Ohm), and higher power dissipation capability (110W vs. 74W). Maintains 400V Vdss rating and D2PAK package compatibility.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Parametric Equivalents):

The IRF730STRLPBF and IRF730STRRPBF are active alternatives to the obsolete IRF730STRL. Both parts maintain identical electrical specifications and D2PAK packaging. Selection between these options depends on procurement requirements:

• IRF730STRLPBF: Tape & Reel packaging format with ROHS3 compliance. Suitable for automated assembly processes requiring continuous reel supply.
• IRF730STRRPBF: Tape & Reel packaging format with ROHS3 compliance and highest inventory availability (2900 units). Recommended for volume production requiring assured supply.

Both parametric equivalents provide RoHS3 compliance, addressing regulatory requirements absent in the original IRF730STRL.

For Enhanced Performance Substitution:

The STB11NK40ZT4 (STMicroelectronics) is a manufacturer-recommended substitute offering superior electrical performance:

• Continuous drain current increased to 9A (63% higher than IRF730STRL)
• On-state resistance reduced to 550mOhm (45% lower than IRF730STRL)
• Power dissipation capability increased to 110W (49% higher than IRF730STRL)
• Gate charge reduced to 32 nC (16% lower than IRF730STRL)
• Extended gate voltage rating to ±30V (vs. ±20V)

The STB11NK40ZT4 maintains 400V Vdss rating and D2PAK package compatibility. This device is suitable for applications where improved thermal performance, reduced conduction losses, or faster switching characteristics provide system benefits. ROHS3 compliance and active product status ensure long-term availability.

Frequently Asked Questions (FAQ)

Q: Can the IRF730STRLPBF directly replace the IRF730STRL in existing designs?

A: Yes. The IRF730STRLPBF is a parametric equivalent with identical electrical specifications. The only differences are packaging format (Tape & Reel vs. bulk) and RoHS3 compliance status. Pin configuration and electrical performance are identical, enabling direct substitution without circuit modification.

Q: What is the primary advantage of the STB11NK40ZT4 over the IRF730STRL?

A: The STB11NK40ZT4 provides enhanced performance across multiple parameters: 63% higher continuous drain current (9A vs. 5.5A), 45% lower on-state resistance (550mOhm vs. 1 Ohm), and 49% higher power dissipation capability (110W vs. 74W). These improvements reduce conduction losses and thermal stress in switching applications.

Q: Are all substitute parts compatible with the D2PAK footprint?

A: Yes. All listed substitutes use the TO-263 (D2PAK) surface mount package with identical pin configuration (2 leads plus tab). PCB footprints and thermal pad layouts are compatible across all parts.

Q: Does the STB11NK40ZT4 require different gate drive circuitry?

A: The STB11NK40ZT4 has a slightly higher gate threshold voltage (4.5V vs. 4V) and lower gate charge (32 nC vs. 38 nC). Existing gate drive circuits designed for the IRF730STRL will function with the STB11NK40ZT4. The lower gate charge may improve switching speed without circuit modification.

Q: What is the significance of RoHS3 compliance in the substitute parts?

A: RoHS3 compliance indicates conformance to Restriction of Hazardous Substances regulations. The original IRF730STRL is RoHS non-compliant, while IRF730STRLPBF, IRF730STRRPBF, and STB11NK40ZT4 are ROHS3 compliant. This compliance is required for many industrial and consumer applications subject to environmental regulations.

Q: Can the IRF730STRR be used as a substitute despite non-RoHS compliance?

A: The IRF730STRR is electrically identical to the IRF730STRL and maintains active product status. However, it retains RoHS non-compliant status. Selection depends on application regulatory requirements. For new designs, ROHS3-compliant alternatives (IRF730STRLPBF or IRF730STRRPBF) are preferred.

Q: What is the difference between IRF730STRLPBF and IRF730STRRPBF?

A: Both parts are parametric equivalents with identical electrical specifications and ROHS3 compliance. The primary difference is inventory availability: IRF730STRRPBF has significantly higher stock (2900 units vs. 784 units). For volume production, IRF730STRRPBF offers superior supply assurance.

Q: Is the STB11NK40ZT4 suitable for all applications using the IRF730STRL?

A: The STB11NK40ZT4 is suitable for applications where the enhanced electrical characteristics provide system benefits or where the original IRF730STRL specifications are marginal. The higher drain current and lower on-state resistance reduce thermal stress. However, applications with strict component qualification requirements may require formal validation before substitution.

Q: What is the input capacitance difference between IRF730STRL and STB11NK40ZT4?

A: The STB11NK40ZT4 has higher input capacitance (930 pF vs. 700 pF). This 33% increase requires proportionally higher gate drive current for equivalent switching speed. Gate drive circuits must supply sufficient current to charge the higher capacitance within required switching time windows.