AO4444 Equivalent & Substitute Parts

Part Overview

The AO4444 is an N-Channel MOSFET manufactured by Alpha & Omega Semiconductor Inc., rated for 80V drain-to-source voltage with 11A continuous drain current at 25°C. The device is housed in an 8-SOIC surface mount package and is part of the SDMOS™ series. The AO4444 is classified as obsolete, making identification of equivalent and substitute parts necessary for ongoing design support, production continuity, and component sourcing.

Substiute Parts

AO4444

Alpha & Omega Semiconductor Inc.In Stock: 1723AO4444 Datasheet

Current PartRFQ

DMT10H010LSS-13

Diodes IncorporatedIn Stock: 3729DMT10H010LSS-13 Datasheet

MFR RecommendedRFQ

SI4056DY-T1-GE3

Vishay SiliconixIn Stock: 20196SI4056DY-T1-GE3 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AO4444 is determined by the following critical parameters:

Electrical Compatibility Requirements:

• FET Type: N-Channel topology must be maintained
• Drain to Source Voltage (Vdss): Substitute must equal or exceed 80V
• Continuous Drain Current (Id): Substitute must meet or exceed 11A at 25°C
• On-State Resistance (Rds On): Substitute must not exceed 12 mOhm at rated conditions to maintain thermal and efficiency characteristics
• Gate Threshold Voltage (Vgs(th)): Must be compatible with existing gate drive circuitry
• Operating Temperature Range: Must support −55°C to 150°C (TJ)

Mechanical Compatibility Requirements:

• Mounting Type: Surface Mount only
• Package: 8-SOIC form factor with 0.154" (3.90mm) width

Regulatory & Compliance Requirements:

• RoHS3 Compliance: Required
• Moisture Sensitivity Level (MSL): Level 1 (Unlimited) preferred
• ECCN Classification: EAR99

The substitute parts listed below meet all electrical, mechanical, and regulatory requirements for direct replacement in applications using the AO4444.

Parameter Comparison

Engineering Selection Recommendations

DMT10H010LSS-13 (Diodes Incorporated)

The DMT10H010LSS-13 is an active product with higher voltage rating (100V vs. 80V) and improved on-state resistance (9.5 mOhm vs. 12 mOhm). It exceeds the continuous drain current requirement at both Ta and Tc conditions. This part is ROHS3 compliant with MSL Level 1 rating. The higher gate charge (71 nC vs. 46 nC) requires verification of gate drive circuit capability. Packaging is 8-SO, which is mechanically compatible with 8-SOIC footprints. This substitute provides superior thermal performance and active product status.

SI4056DY-T1-GE3 (Vishay Siliconix)

The SI4056DY-T1-GE3 is an active product with 100V voltage rating and meets the continuous drain current requirement. It features the lowest gate charge (29.5 nC vs. 46 nC), reducing gate drive power requirements. However, the on-state resistance specification (23 mOhm @ 15A, 10V) is higher than the AO4444 baseline, which may impact thermal performance in current-limited applications. The part is ROHS3 compliant with MSL Level 1 rating and uses the TrenchFET® technology platform. Packaging is 8-SOIC, providing direct footprint compatibility. This substitute is suitable for applications where lower gate charge is advantageous.

Both substitutes maintain full compatibility with the AO4444 in terms of operating temperature range, regulatory compliance, and surface mount assembly requirements.

Frequently Asked Questions (FAQ)

Q: Can the DMT10H010LSS-13 and SI4056DY-T1-GE3 be used interchangeably with the AO4444?

A: Both parts meet the core electrical and mechanical requirements for substitution. However, differences in gate charge and on-state resistance specifications require circuit-level evaluation. The DMT10H010LSS-13 has lower Rds On but higher gate charge. The SI4056DY-T1-GE3 has lower gate charge but higher Rds On. Selection depends on whether the application is gate-drive limited or thermal-performance limited.

Q: What is the significance of the higher Vdss rating (100V) in the substitute parts?

A: The 100V rating in both substitutes exceeds the AO4444's 80V specification, providing additional voltage margin. This does not create incompatibility; it simply allows operation at higher voltages if required. For applications limited to 80V operation, both substitutes remain fully functional.

Q: Are the 8-SO and 8-SOIC packages mechanically compatible?

A: Yes. Both 8-SO and 8-SOIC packages share the same 0.154" (3.90mm) width and pin pitch, allowing direct PCB footprint compatibility. The DMT10H010LSS-13 (8-SO) and SI4056DY-T1-GE3 (8-SOIC) can be soldered into existing AO4444 board layouts without modification.

Q: How do gate charge differences affect circuit design?

A: Gate charge (Qg) determines the energy required to switch the MOSFET. The SI4056DY-T1-GE3 (29.5 nC) requires less gate drive energy than the AO4444 (46 nC), while the DMT10H010LSS-13 (71 nC) requires more. If the existing gate drive circuit has limited current capability, the SI4056DY-T1-GE3 is preferred. If gate drive current is not constrained, the DMT10H010LSS-13 is acceptable.

Q: What does the higher on-state resistance in the SI4056DY-T1-GE3 mean for thermal design?

A: On-state resistance (Rds On) directly affects power dissipation during conduction. The SI4056DY-T1-GE3 (23 mOhm @ 15A, 10V) dissipates more heat than the AO4444 (12 mOhm @ 11A, 10V) at equivalent current levels. Applications with high continuous current or limited thermal dissipation may require additional heatsinking or selection of the DMT10H010LSS-13 instead.

Q: Are all three parts RoHS3 compliant?

A: Yes. The AO4444, DMT10H010LSS-13, and SI4056DY-T1-GE3 are all ROHS3 compliant with MSL Level 1 (Unlimited) moisture sensitivity rating, meeting current environmental and reliability standards.

Q: Why is the AO4444 classified as obsolete?

A: Obsolete status indicates the part is no longer manufactured by Alpha & Omega Semiconductor Inc. The substitute parts listed are active products from established manufacturers, ensuring long-term availability and supply chain continuity.