AO4485 P-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The AO4485 is a P-Channel MOSFET manufactured by Alpha & Omega Semiconductor Inc., rated for 40V drain-to-source voltage with 10A continuous drain current at 25°C. This device is housed in an 8-SOIC surface mount package and is classified as Active product status with full RoHS3 compliance. The AO4485 serves applications requiring P-Channel switching and linear regulation in power management circuits, gate driver applications, and load switching configurations.

Equivalent and substitute parts are identified based on matching or exceeding critical electrical parameters while maintaining compatible package footprints and operating characteristics. Substitution becomes necessary when the primary part reaches end-of-life status, inventory constraints occur, or design optimization requires enhanced performance specifications.

Substiute Parts

AO4485

Alpha & Omega Semiconductor Inc.In Stock: 90125AO4485 Datasheet

Current PartRFQ

FDS4675

onsemiIn Stock: 16610FDS4675 Datasheet

MFR RecommendedRFQ

FDS4685

onsemiIn Stock: 18602FDS4685 Datasheet

MFR RecommendedRFQ

IRF7240TRPBF

Infineon TechnologiesIn Stock: 4085IRF7240TRPBF Datasheet

MFR RecommendedRFQ

SQ4401EY-T1_GE3

Vishay SiliconixIn Stock: 1995SQ4401EY-T1_GE3 Datasheet

MFR RecommendedRFQ

AO4485

UMWIn Stock: 90167AO4485 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the AO4485 are classified based on the following substitution criteria:

Primary Matching Parameters:

• FET Type: P-Channel (mandatory)
• Drain to Source Voltage (Vdss): 40V (mandatory)
• Package: 8-SOIC or 8-SO surface mount (mandatory for PCB compatibility)
• Mounting Type: Surface Mount (mandatory)
• Continuous Drain Current (Id): Equal to or greater than 10A
• Rds On (Max): Equal to or less than 15mOhm at rated conditions
• Gate Threshold Voltage (Vgs(th)): Within ±20V gate voltage specification
• Operating Temperature: Minimum -55°C to 150°C overlap required

Substitution Categories:

Category 1: Direct Parametric Equivalents — Parts with identical or superior electrical specifications and active product status. These parts maintain the same performance envelope as the AO4485.

Category 2: Enhanced Performance Substitutes — Parts exceeding the AO4485 specifications in drain current capacity or power dissipation while maintaining voltage and package compatibility. These parts provide design margin and thermal headroom.

Category 3: Parametric Equivalents with Obsolete Status — Parts meeting all electrical and package requirements but classified as Obsolete. These are suitable for legacy design support or inventory management only.

Category 4: Alternate Manufacturer Equivalents — Parts from different manufacturers meeting identical specifications, providing supply chain flexibility and multi-source availability.

Parameter Comparison

Engineering Selection Recommendations

For Active Product Status Applications:

The FDS4675 (onsemi PowerTrench® series) provides enhanced performance with 11A continuous drain current and 13mOhm Rds On, exceeding AO4485 specifications while maintaining 40V Vdss and 8-SOIC package compatibility. Extended operating temperature to 175°C provides additional thermal margin. This part is recommended for new designs requiring performance optimization.

The IRF7240TRPBF (Infineon HEXFET® series) delivers 10.5A continuous drain current with 15mOhm Rds On, matching AO4485 performance envelope. The 8-SO package maintains PCB footprint compatibility. This part is suitable for direct substitution in existing designs.

The AO4485 from UMW represents a parametric equivalent manufactured by an alternate source, providing identical electrical specifications and package configuration. This part maintains supply chain flexibility for the original AO4485 specification.

The FDS4685 (onsemi PowerTrench® series) operates at 8.2A continuous drain current with 27mOhm Rds On. This part is suitable only for applications where the 10A current requirement can be reduced or where lower current operation is acceptable. Higher on-resistance increases power dissipation in switching applications.

For Legacy Design Support:

The SQ4401EY-T1_GE3 (Vishay TrenchFET® series) is classified as Obsolete but remains available in limited inventory (1955 pcs). This part delivers superior performance with 17.3A continuous drain current and 14mOhm Rds On, with extended operating temperature to 175°C. This part is restricted to legacy design maintenance and end-of-life support only. New designs must not incorporate this part.

Compliance and Certification:

All recommended substitute parts maintain RoHS3 compliance, MSL Level 1 (Unlimited moisture sensitivity), and EAR99 export classification, matching the AO4485 regulatory profile. REACH status is either REACH Unaffected or Vendor Undefined, consistent with semiconductor industry standards.

Frequently Asked Questions (FAQ)

Q: Can the FDS4675 directly replace the AO4485 in existing PCB designs?

A: The FDS4675 maintains 8-SOIC package compatibility and identical pin configuration with the AO4485. Electrical specifications are superior (11A vs. 10A, 13mOhm vs. 15mOhm Rds On). Direct substitution is permissible without PCB modification. Verify gate drive voltage compatibility (both require 4.5V to 10V drive range).

Q: What is the difference between the 8-SOIC and 8-SO package designations?

A: Both 8-SOIC and 8-SO refer to surface mount small-outline packages with 0.154" (3.90mm) width. These packages are mechanically and electrically compatible for PCB assembly. Pin pitch and lead configuration are identical, permitting direct substitution without PCB redesign.

Q: Why does the SQ4401EY-T1_GE3 show Obsolete status?

A: Obsolete status indicates the manufacturer has discontinued production and removed the part from active distribution. While limited inventory remains available, this part is not recommended for new designs. Obsolete parts are reserved for legacy system maintenance and repair applications only.

Q: Is the AO4485 from UMW identical to the Alpha & Omega AO4485?

A: The UMW AO4485 maintains identical electrical specifications, voltage ratings, current capacity, and package configuration as the Alpha & Omega AO4485. Both parts are Active status with full RoHS3 compliance. The UMW variant provides alternate source availability for supply chain continuity.

Q: How does gate charge (Qg) affect substitution suitability?

A: Gate charge determines the energy required to switch the MOSFET on and off. The AO4485 specifies 55nC at 10V. Substitute parts with higher gate charge (IRF7240TRPBF at 110nC, SQ4401EY-T1_GE3 at 115nC) require higher gate drive current and may increase switching losses. Lower gate charge (FDS4685 at 27nC) reduces drive requirements. Gate drive circuit design must accommodate the selected part's gate charge specification.

Q: Can the FDS4685 be used in applications requiring 10A continuous current?

A: The FDS4685 is rated for 8.2A continuous drain current, below the AO4485 10A specification. Using this part in 10A applications exceeds its rated current capacity and violates electrical design margins. The FDS4685 is suitable only for applications where the actual current requirement is 8.2A or less.

Q: What is the significance of the extended operating temperature range in FDS4675 and SQ4401EY-T1_GE3?

A: The FDS4675 and SQ4401EY-T1_GE3 specify -55°C to 175°C operating range, compared to the AO4485 -55°C to 150°C range. The extended upper temperature limit provides additional thermal margin in high-temperature environments. This specification difference does not affect substitution suitability for applications operating within the AO4485 temperature range.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All recommended substitute parts (FDS4675, FDS4685, IRF7240TRPBF, SQ4401EY-T1_GE3, and UMW AO4485) maintain RoHS3 compliance and MSL Level 1 rating, matching the original AO4485 environmental and regulatory specifications.