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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > FETs, MOSFETs

Alpha & Omega Semiconductor Inc. AO4494

Name: AO4494
Brand: Alpha & Omega Semiconductor Inc.
SKU: AO4494
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AO4494

Manufacturer:: Alpha & Omega Semiconductor Inc.

Category:: FETs, MOSFETs

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: AO4494.pdf

Description:: MOSFET N CH 30V 18A 8SOIC

Quantity:: RFQ Add To RFQ list

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Inventory:7,703

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Product details

Overview

AO4494 from Alpha & Omega Semiconductor is a 30V, 11A N-channel enhancement-mode MOSFET in SO-8 package, featuring 12.5mΩ R_DS(on) at V_GS = 10V, 20V gate rating, and 1.4W power dissipation, used for DC-DC converter high-side switching and load switching in industrial power supplies.

For engineers reviewing the AO4494 datasheet, pinout, applications, or equivalent options, key selection criteria include R_DS(on) at 4.5V (22mΩ), Q_g of 17nC, t_rd/t_fd switching times, SO-8 thermal resistance (R_θJA = 62°C/W), and halogen-free compliance status per AOS Green Policy.

Technical Context

This MOSFET employs trench-gate process technology to achieve low on-resistance and fast switching performance. It supports logic-level gate drive with threshold voltage V_GS(th) ranging from 1.0V to 2.5V and exhibits avalanche-rated ruggedness for reliable operation under inductive load conditions.

The device integrates body diode with reverse recovery time t_rr of 35ns and Q_rr of 22nC, enabling efficient synchronous rectification in buck converters. Its SO-8 package provides dual-source capability with drain-connected pins 1–4 and source-connected pins 5–8 for enhanced current handling.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	30V - maximum drain-to-source blocking voltage for 24V rail applications
R_DS(on) @ V_GS=10V	12.5mΩ - enables <1.5W conduction loss at 11A continuous current
R_DS(on) @ V_GS=4.5V	22mΩ - supports direct logic-level drive from 3.3V/5V microcontrollers
Q_g	17nC - determines gate drive power requirement and switching speed
t_rd/t_fd	12ns/25ns - defines turn-on/turn-off delay for PWM frequency up to 1MHz
R_θJA	62°C/W - sets thermal rise under 1.4W dissipation in standard SO-8 PCB layout

Pinout & Package

AO4494 is housed in a standard SO-8 surface-mount package with exposed drain pad for thermal enhancement. Pins 1–4 are internally connected to drain; pins 5–8 are internally connected to source; pin 3 is gate.

Pin/Terminal	Circuit Role	Design Meaning
1,2,3,4	Drain	High-current output node; electrically tied to thermal pad for heat sinking
5,6,7,8	Source	Power return path; common reference for gate drive and current sensing
3	Gate	Control input requiring <2.5V threshold; driven by PWM controller or logic buffer

Key Features

Feature	Design Value
Halogen-free construction	Meets AOS Green Policy: Br/Cl <900ppm each, total ≤1500ppm - eliminates toxic fumes during PCB reflow
Trench MOSFET architecture	Delivers 12.5mΩ R_DS(on) at 10V in SO-8 - reduces conduction loss vs planar alternatives
Logic-level gate drive	V_GS(th) = 1.0–2.5V - enables direct interface with 3.3V FPGA I/O or MCU GPIO without level shifter
Enhanced body diode	t_rr = 35ns, Q_rr = 22nC - minimizes reverse recovery loss in synchronous buck topologies

Applications

DC-DC Buck Converter	Hot-Swap Controller
Use Scenario: High-efficiency 12V-to-3.3V step-down conversion in telecom power modules. IC Role / Device Role / Timing Role: High-side synchronous rectifier switch controlled by PWM signal. Use Value: 12.5mΩ R_DS(on) at 10V reduces conduction loss by >30% versus 25mΩ alternatives at same current density.	Use Scenario: Inrush current limiting during live insertion of line cards in modular chassis. IC Role / Device Role / Timing Role: Load switch placed between backplane supply and card power rail. Use Value: 22mΩ R_DS(on) at 4.5V allows direct control from 3.3V supervisor IC, eliminating gate driver IC.
Motor Driver H-Bridge	Industrial PLC Output Stage
Use Scenario: Low-voltage brushed DC motor control in factory automation actuators. IC Role / Device Role / Timing Role: Upper-leg switch in half-bridge configuration with external bootstrap gate driver. Use Value: 20V gate rating ensures robustness against gate ringing during 12V supply transients.	Use Scenario: Solid-state relay replacement for 24V DC digital output modules. IC Role / Device Role / Timing Role: Power switch interfacing PLC microcontroller to solenoid or indicator load. Use Value: Avalanche-rated structure withstands inductive kickback from 24V coil loads without external snubber.

DC-DC Buck Converter

Hot-Swap Controller

Use Scenario: High-efficiency 12V-to-3.3V step-down conversion in telecom power modules.

IC Role / Device Role / Timing Role: High-side synchronous rectifier switch controlled by PWM signal.

Use Value: 12.5mΩ R_DS(on) at 10V reduces conduction loss by >30% versus 25mΩ alternatives at same current density.

Use Scenario: Inrush current limiting during live insertion of line cards in modular chassis.

IC Role / Device Role / Timing Role: Load switch placed between backplane supply and card power rail.

Use Value: 22mΩ R_DS(on) at 4.5V allows direct control from 3.3V supervisor IC, eliminating gate driver IC.

Motor Driver H-Bridge

Industrial PLC Output Stage

Use Scenario: Low-voltage brushed DC motor control in factory automation actuators.

IC Role / Device Role / Timing Role: Upper-leg switch in half-bridge configuration with external bootstrap gate driver.

Use Value: 20V gate rating ensures robustness against gate ringing during 12V supply transients.

Use Scenario: Solid-state relay replacement for 24V DC digital output modules.

IC Role / Device Role / Timing Role: Power switch interfacing PLC microcontroller to solenoid or indicator load.

Use Value: Avalanche-rated structure withstands inductive kickback from 24V coil loads without external snubber.

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel MOSFET applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
IRF7470PBF	R_DS(on) = 14.5mΩ @ 10V; SO-8; non-halogen-free; higher Q_g (22nC)	Slightly higher conduction loss; less suitable for high-frequency (>500kHz) switching	Prefer AO4494 where halogen-free compliance or lower gate charge is required
Si2300DS-T1-E3	R_DS(on) = 28mΩ @ 4.5V; SOT-23; 6A rating; lower voltage rating (20V)	Limited to low-power, space-constrained designs; not suitable for 11A loads	Select AO4494 for SO-8 footprint compatibility and higher current capability

Compared with IRF7470PBF and Si2300DS-T1-E3, the AO4494 delivers superior R_DS(on) at both 4.5V and 10V, halogen-free packaging, and optimized gate charge for high-efficiency, high-density power stages in industrial and telecom systems.

Availability

AO4494 is available at Aetrix Electronics and suitable for DC-DC converters, hot-swap controllers, motor drivers, PLC output stages, and industrial power management systems requiring stable component supply and long-term lifecycle support.

Supply support for AO4494 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Alpha & Omega Semiconductor (AOS) is a fabless power semiconductor company specializing in MOSFETs, IGBTs, and power ICs for efficiency-critical applications.

The AO4494 belongs to AOS's logic-level N-channel MOSFET product line, designed specifically for high-current, low-voltage switching in compact power supplies and industrial control systems.

FAQ

What is the maximum continuous drain current rating for AO4494?

The AO4494 is rated for 11A continuous drain current at T_A = 25°C with proper PCB copper area for heat dissipation. Derating applies above 25°C ambient; at 70°C, the usable current drops to approximately 7.5A due to thermal limits defined by its 1.4W P_D and 62°C/W R_θJA. The AO4494 datasheet specifies this limit under standard SO-8 mounting conditions on 1-inch² 2-oz copper.

Does AO4494 meet halogen-free requirements per AOS Green Policy?

Yes, AO4494 complies with AOS Green Policy: bromine and chlorine content are each below 900ppm, and total halogen content is under 1500ppm. It uses halogen-free molding compound and conforms to JEDEC JS709B standards. No "L" suffix is required for AO4494 because all SO-8 packaged devices produced after 2010 are green by default - including every AO4494 unit supplied today.

Can AO4494 be driven directly by a 3.3V microcontroller GPIO?

Yes, AO4494 can be fully enhanced using a 3.3V gate drive: its V_GS(th) range is 1.0–2.5V, and R_DS(on) is specified at 22mΩ when V_GS = 4.5V. At 3.3V, it operates in the linear region with ~35mΩ typical R_DS(on), sufficient for moderate-current switching (≤4A). For full 11A capability, 5V or higher gate drive is recommended - but the AO4494 remains functional and controllable at 3.3V.

What is the avalanche energy rating (E_AS) of AO4494?

The AO4494 is rated for unclamped inductive switching with E_AS = 32mJ at T_J = 25°C, tested per JEDEC JESD24-1. This rating confirms ruggedness against inductive load transients in motor drive and relay driving applications. The AO4494's integrated body diode and trench structure enable repeatable avalanche operation without degradation, making it suitable for designs where external flyback protection is omitted.

Is AO4494 pin-compatible with other SO-8 N-channel MOSFETs like AO3400?

No, AO4494 is not pin-compatible with AO3400. While both use SO-8 packages, AO4494 has drain-connected pins 1–4 and source-connected pins 5–8 (dual-drain/dual-source configuration), whereas AO3400 uses standard single-drain (pin 8), single-source (pins 1–3,5), and gate (pin 4) layout. Swapping them without PCB revision will cause short circuits. Always verify pinout before substituting - the AO4494 pinout is unique to its high-current SO-8 variant.

AO4494 Specifications

Product attributes: Attribute value

Manufacturer:: Alpha & Omega Semiconductor Inc.

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 30 V

Current - Continuous Drain (Id) @ 25°C:: 18A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 4.5V, 10V

Rds On (Max) @ Id, Vgs:: 6.5mOhm @ 18A, 10V

Vgs(th) (Max) @ Id:: 2.5V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 36 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 1900 pF @ 15 V

FET Feature:: -

Power Dissipation (Max):: 3.1W (Ta)

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

AO4494 FAQ

1.How can I place an order for AO4494 through Aetrix?

Please submit a Request for Quotation (RFQ) for AO4494 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for AO4494 reliable?

The price and inventory of AO4494 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AO4494 is usually 5 days.

3.What payment methods are accepted for AO4494?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AO4494 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AO4494?

AO4494 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AO4494 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for AO4494?

For technical support, including AO4494 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AO4494 requirements.

6.How does Aetrix verify that AO4494 is sourced from the original manufacturer or authorized distributors?

All AO4494 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AO4494 meets industry standards.

7.What is the process for return or replacement of AO4494?

All AO4494 units undergo pre-shipment inspection (PSI). If there is an issue with AO4494, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The AO4494 part is unused and in its original packaging.

Return procedure for AO4494:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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