IRLU7843PBF N-Channel 30V 161A MOSFET Equivalent & Substitute Parts

Part Overview

The IRLU7843PBF is an N-Channel MOSFET manufactured by Infineon Technologies, part of the HEXFET® series. This through-hole device operates at 30V drain-to-source voltage with a continuous drain current rating of 161A at 25°C and maximum power dissipation of 140W. The component is packaged in IPAK (TO-251AA) format with short leads for through-hole mounting.

The IRLU7843PBF carries a product status designation of "Not For New Designs," indicating that Infineon has discontinued active development and recommendation for new applications. This status necessitates identification of functionally equivalent substitute components that maintain electrical and mechanical compatibility while meeting current design standards and compliance requirements.

Substiute Parts

IRLU7843PBF

Infineon TechnologiesIn Stock: 906IRLU7843PBF Datasheet

Current PartRFQ

IRLU8743PBF

Infineon TechnologiesIn Stock: 2092IRLU8743PBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRLU7843PBF is determined by strict equivalence across the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Drain-to-Source Voltage (Vdss): Must equal or exceed 30V
• Continuous Drain Current (Id): Must equal or exceed 161A at 25°C
• Gate Threshold Voltage (Vgs(th)): Must fall within acceptable operating range
• On-State Resistance (Rds On): Must not exceed specified maximum values
• Power Dissipation: Must support thermal requirements

Mechanical Compatibility Criteria:

• Package Type: IPAK (TO-251AA) with short leads
• Mounting Type: Through-hole configuration
• Pin Configuration: TO-251-3 standard

Compliance Criteria:

• RoHS3 Compliance: Required
• Moisture Sensitivity Level (MSL): Level 1 (Unlimited)
• REACH Status: Unaffected

The IRLU8743PBF qualifies as a direct substitute based on matching electrical specifications within acceptable tolerance ranges and identical mechanical packaging.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: IRLU8743PBF

The IRLU8743PBF is the manufacturer-recommended equivalent for the IRLU7843PBF. Both components share identical voltage ratings (30V Vdss), equivalent current handling (160A vs. 161A), matching package specifications (IPAK TO-251AA), and identical compliance certifications (ROHS3, MSL Level 1).

The IRLU8743PBF demonstrates superior on-state resistance characteristics (3.1 mOhm at 25A versus 3.3 mOhm at 15A), resulting in lower conduction losses in high-current applications. Gate charge and input capacitance show minor increases (59 nC and 4880 pF respectively) within acceptable engineering tolerances. Power dissipation rating of 135W remains adequate for thermal management in equivalent circuit topologies.

Both components carry "Not For New Designs" status from Infineon, reflecting the maturity of the HEXFET® technology platform. Selection between these parts should be based on inventory availability and specific thermal design requirements of the application circuit.

Frequently Asked Questions (FAQ)

Q: Can the IRLU8743PBF directly replace the IRLU7843PBF in existing designs?

A: Yes. The IRLU8743PBF maintains electrical equivalence across all critical parameters: identical 30V voltage rating, equivalent 160A continuous current (versus 161A), matching IPAK TO-251AA package, and identical compliance certifications. Pin configuration and through-hole mounting are identical.

Q: What are the differences in on-state resistance between these parts?

A: The IRLU7843PBF specifies 3.3 mOhm maximum at 15A and 10V gate voltage. The IRLU8743PBF specifies 3.1 mOhm maximum at 25A and 10V gate voltage. The IRLU8743PBF exhibits lower resistance, reducing conduction losses. Both values fall within acceptable operating parameters for equivalent circuit performance.

Q: Are there thermal management differences?

A: The IRLU7843PBF is rated for 140W maximum power dissipation; the IRLU8743PBF is rated for 135W. Both ratings support equivalent thermal designs when proper heat sinking is implemented. Circuit thermal analysis should verify that the 5W difference does not impact specific application requirements.

Q: Do these parts require different gate drive circuits?

A: No. Both components specify identical maximum gate voltage (±20V) and equivalent gate threshold voltages (2.3V and 2.35V respectively). Gate charge differs slightly (50 nC versus 59 nC at 4.5V), representing acceptable variance that does not require gate driver circuit modification.

Q: Are the packages physically identical?

A: Yes. Both components use IPAK (TO-251AA) packaging with short leads for through-hole mounting. PCB footprints, lead spacing, and mounting hole requirements are identical. No PCB redesign is necessary for substitution.

Q: What is the significance of "Not For New Designs" status?

A: This designation indicates that Infineon has concluded active development and marketing of these components. Existing inventory remains available and fully functional. For new product development, evaluation of current-generation alternatives may be prudent for long-term supply chain planning, though these parts remain suitable for legacy system maintenance and repair.

Q: Are compliance certifications identical?

A: Yes. Both the IRLU7843PBF and IRLU8743PBF carry ROHS3 compliance, MSL Level 1 (Unlimited) moisture sensitivity rating, REACH Unaffected status, and identical ECCN and HTSUS classifications. No compliance documentation changes are required for substitution.