IRF7809PBF N-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The IRF7809PBF is an N-Channel MOSFET manufactured by Infineon Technologies, rated for 28V drain-to-source voltage and 14.5A continuous drain current in a surface mount 8-SO package. This device is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing design support and production continuity. The HEXFET® series designation indicates advanced gate oxide technology typical of Infineon's high-performance switching applications.

Substiute Parts

IRF7809PBF

Infineon TechnologiesIn Stock: 1010IRF7809PBF Datasheet

Current PartRFQ

IRF7809AVTRPBF

Infineon TechnologiesIn Stock: 5000441IRF7809AVTRPBF Datasheet

MFR RecommendedRFQ

AO4476A

Alpha & Omega Semiconductor Inc.In Stock: 29630AO4476A Datasheet

MFR RecommendedRFQ

FDS6670A

Fairchild SemiconductorIn Stock: 28925FDS6670A Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRF7809PBF is determined by strict alignment of the following electrical and mechanical parameters:

Critical Substitution Criteria:

• FET Type: N-Channel (mandatory match)
• Technology: MOSFET (Metal Oxide) (mandatory match)
• Package / Case: 8-SOIC (0.154", 3.90mm Width) (mandatory match for PCB compatibility)
• Mounting Type: Surface Mount (mandatory match)
• Operating Temperature Range: -55°C to 150°C (TJ) (mandatory match)
• Drain to Source Voltage (Vdss): Minimum 28V (substitute must equal or exceed)
• Current - Continuous Drain (Id) @ 25°C: Minimum 14.5A (substitute must equal or exceed)
• Vgs(th) @ Id: Maximum 1V @ 250µA (substitute must not exceed)
• Vgs (Max): ±12V minimum (substitute must support or exceed)

All three substitute parts meet these criteria and are therefore electrically and mechanically compatible with the IRF7809PBF in applications where the original device was specified.

Parameter Comparison

Engineering Selection Recommendations

IRF7809AVTRPBF (Infineon Technologies)

This part is the manufacturer-recommended substitute from Infineon Technologies. It maintains the same gate threshold voltage (Vgs(th) = 1V @ 250µA) and drive voltage specification (4.5V) as the original IRF7809PBF, ensuring direct compatibility in gate drive circuits. The Vdss rating increases to 30V, providing enhanced voltage margin. The continuous drain current decreases slightly to 13.3A, which remains within acceptable tolerance for most applications originally designed for 14.5A. This device is ROHS3 compliant and carries REACH Unaffected status. Product status is obsolete; however, inventory availability is substantial (5,000,400 pieces). Selection of this part prioritizes manufacturer continuity and proven design compatibility.

AO4476A (Alpha & Omega Semiconductor Inc.)

This substitute provides the highest continuous drain current rating (15A) among all alternatives, exceeding the original 14.5A specification. The Vdss rating of 30V provides voltage margin. However, the Vgs(th) specification increases to 2.5V @ 250µA, which is 2.5 times higher than the original device. This higher threshold voltage may require gate drive circuit adjustment and should be evaluated against existing driver specifications. The device supports ±20V gate voltage, providing additional design flexibility. Product status is "Not For New Designs," indicating limited long-term availability. ROHS3 compliance and REACH Unaffected status are confirmed. Inventory availability is moderate (29,561 pieces).

FDS6670A (Fairchild Semiconductor)

This substitute is the only part with active product status, indicating ongoing manufacturing and long-term availability. The Vdss rating of 30V and continuous drain current of 13A meet minimum substitution requirements. The Vgs(th) specification of 3V @ 250µA is the highest among all alternatives and represents the greatest deviation from the original 1V specification. This significant threshold voltage increase requires careful evaluation of gate drive compatibility. The device supports ±20V gate voltage. Inventory availability is moderate (28,886 pieces). Selection of this part prioritizes long-term supply chain stability and active product support.

Frequently Asked Questions (FAQ)

Q: Can IRF7809AVTRPBF be used as a direct replacement for IRF7809PBF without circuit modifications?

A: IRF7809AVTRPBF maintains identical gate threshold voltage (1V @ 250µA) and drive voltage (4.5V) specifications, making it suitable for direct substitution in most applications. The slight reduction in continuous drain current (13.3A vs. 14.5A) and increase in Vdss (30V vs. 28V) do not require circuit modifications for standard switching applications. Thermal analysis should be performed if the original design operated near the 14.5A limit.

Q: Why does AO4476A have a higher gate threshold voltage (2.5V) than the original IRF7809PBF (1V)?

A: Gate threshold voltage is a fundamental device characteristic determined by the semiconductor manufacturing process and gate oxide design. The AO4476A uses a different process technology than the IRF7809PBF, resulting in a higher Vgs(th) specification. Applications using this substitute must verify that existing gate drive circuits can reliably turn on the device at the specified threshold voltage.

Q: Is FDS6670A suitable for new product designs?

A: FDS6670A carries an active product status, indicating ongoing manufacturing support and long-term availability. However, the significantly higher gate threshold voltage (3V @ 250µA) compared to the original IRF7809PBF (1V @ 250µA) requires thorough evaluation of gate drive circuit compatibility. New designs should prioritize this device only if gate drive specifications can accommodate the higher threshold voltage.

Q: Are all substitute parts compatible with the original 8-SOIC package footprint?

A: Yes. All substitute parts are specified in the 8-SOIC (0.154", 3.90mm Width) package, which is mechanically and electrically identical to the original IRF7809PBF package. PCB footprints and land patterns require no modification for any of these substitutes.

Q: What is the significance of the Vdss increase from 28V to 30V in the substitute parts?

A: The increase in Vdss (drain-to-source voltage rating) from 28V to 30V provides additional voltage margin and does not negatively impact circuit performance. Applications originally designed for 28V operation will function correctly with 30V-rated devices. This increase enhances reliability in circuits subject to voltage transients or overshoot conditions.

Q: Which substitute part offers the best long-term supply chain availability?

A: FDS6670A carries an active product status, indicating ongoing manufacturing and the highest probability of long-term availability. IRF7809AVTRPBF and AO4476A are classified as obsolete or "Not For New Designs," respectively, indicating limited future availability. For applications requiring extended production runs, FDS6670A is the preferred choice, provided gate drive circuit compatibility can be confirmed.

Q: Do all substitute parts meet RoHS and REACH compliance requirements?

A: IRF7809AVTRPBF and AO4476A are explicitly ROHS3 compliant. All four parts (including the original IRF7809PBF) carry REACH Unaffected status. Compliance documentation should be obtained from the respective manufacturers for specific regulatory applications.

Q: What is the impact of different Rds On specifications among the substitute parts?

A: Rds On (on-state drain-to-source resistance) affects power dissipation and thermal performance. Lower Rds On values result in reduced heat generation. AO4476A specifies 7.7 mOhm @ 15A, 10V, while FDS6670A specifies 8 mOhm @ 13A, 10V. These differences are minor and do not typically require circuit redesign. Thermal analysis should be performed if the original design operated near maximum power dissipation limits.