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

Alpha & Omega Semiconductor Inc. AO4409

Name: AO4409
Brand: Alpha & Omega Semiconductor Inc.
SKU: AO4409
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AO4409

Manufacturer:: Alpha & Omega Semiconductor Inc.

Category:: FETs, MOSFETs

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

Datasheet:: AO4409.pdf

Description:: MOSFET P-CH 30V 15A 8SOIC

Quantity:: RFQ Add To RFQ list

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Product details

Overview

AO4409 from Alpha & Omega Semiconductor is a P-channel enhancement-mode MOSFET in SO-8 package, rated for -30 V V_DS, -15 A continuous drain current at T_C = 25°C, and 15 mΩ typical R_DS(on) at V_GS = -10 V. It serves as a high-side load switch in DC-DC converter synchronous rectification and battery protection circuits.

For engineers reviewing the AO4409 datasheet, pinout, applications, or equivalent options, key selection criteria include its logic-level gate drive compatibility (V_GS(th) = -1.0 to -2.5 V), low R_DS(on) at -4.5 V, thermal resistance (R_θJA = 50°C/W), and RoHS-compliant halogen-free construction per AOS Green Policy.

Technical Context

The AO4409 uses trench-gate process technology to achieve low on-resistance and fast switching performance. Its P-channel structure enables simple high-side configuration without level-shifting circuitry, and it supports gate drive voltages down to -4.5 V for direct microcontroller interface.

Thermal design is supported by the SO-8 package's exposed drain pad, which provides low R_θJC (2.5°C/W) and facilitates PCB copper pour heat sinking. The device is specified for operation from -55°C to +150°C junction temperature.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	-30 V - Maximum drain-source voltage before avalanche breakdown; defines safe operating range in negative-rail applications.
I_D (continuous)	-15 A @ T_C = 25°C - Continuous current capability with adequate heatsinking; derates to ~9 A at T_C = 100°C.
R_DS(on) (typ)	15 mΩ @ V_GS = -10 V - Low conduction loss enabling <1.5 W dissipation at 10 A; critical for efficiency in battery-powered systems.
V_GS(th)	-1.0 to -2.5 V - Gate threshold range confirming reliable turn-on with standard 3.3 V or 5 V logic outputs.
Q_g (total)	34 nC @ V_GS = -10 V - Total gate charge determining drive strength requirement and switching loss in PWM applications.
R_θJA	50°C/W - Junction-to-ambient thermal resistance on standard 1-in² FR-4 board; sets maximum power before thermal shutdown.

Pinout & Package

AO4409 is housed in a surface-mount SO-8 package with exposed drain pad (pin 1–4 and 6–8 source/drain/gate connections; pin 5 is drain tab). The package supports reflow soldering per JEDEC J-STD-020 and provides mechanical robustness for automotive and industrial environments.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3, 4	Source	Common source connection; tied to ground or negative rail in high-side switch configuration.
5	Drain (exposed pad)	Main current path output; electrically and thermally connected to PCB copper pour for heat dissipation.
6, 7, 8	Drain	Parallel drain terminals reducing current density and improving thermal spreading from die to package.
Gate	Control input	Accepts logic-level voltage (-4.5 V to -10 V) to fully enhance channel; requires no external level shifter.

Key Features

Feature	Design Value
Logic-level gate drive	Turns on fully with -4.5 V V_GS, enabling direct interface with 3.3 V/5 V microcontrollers and PMICs.
Low R_DS(on)	15 mΩ at -10 V reduces I²R losses in high-current paths, extending battery life in portable equipment.
Halogen-free construction	Complies with AOS Green Policy (Br/Cl < 900 ppm each, total < 1500 ppm); meets IPC-4101D and JEDEC JESD201A standards.
SO-8 with exposed drain	Enables efficient thermal transfer to PCB; R_θJC = 2.5°C/W allows higher sustained power than standard SO-8.

Applications

Battery Protection Circuit	DC-DC Synchronous Rectifier
Use Scenario: Reverse-current blocking and over-discharge cutoff in 2-cell Li-ion battery packs. IC Role / Device Role / Timing Role: P-channel MOSFET used as back-to-back switch with AO4407 or similar to control charge/discharge paths. Use Value: Low R_DS(on) minimizes voltage drop across protection FET, preserving usable battery capacity and runtime.	Use Scenario: High-efficiency buck converter output stage in point-of-load regulators for FPGA or ASIC core supplies. IC Role / Device Role / Timing Role: Synchronous rectifier replacing Schottky diode to reduce conduction loss during low-side conduction phase. Use Value: 15 mΩ R_DS(on) cuts forward voltage drop to ~150 mV at 10 A, improving conversion efficiency by 2–3% vs. diode solution.
Load Switch for Industrial PLC	Hot-Swap Controller Interface
Use Scenario: Controlled power-up of field I/O modules in programmable logic controllers with surge and short-circuit protection. IC Role / Device Role / Timing Role: High-side switch isolating downstream loads; driven by isolated GPIO or dedicated load switch controller. Use Value: Logic-level gate enables direct control from 3.3 V digital isolators; SO-8 footprint simplifies layout in space-constrained DIN-rail modules.	Use Scenario: Inrush current limiting and fault isolation in modular server backplanes with hot-plug capability. IC Role / Device Role / Timing Role: Main pass element in discrete hot-swap circuit, paired with current-sense amplifier and comparator. Use Value: Fast turn-off (t_f = 25 ns) and low Q_g support precise current-limit response and minimize fault energy during overcurrent events.

Battery Protection Circuit

DC-DC Synchronous Rectifier

Use Scenario: Reverse-current blocking and over-discharge cutoff in 2-cell Li-ion battery packs.

IC Role / Device Role / Timing Role: P-channel MOSFET used as back-to-back switch with AO4407 or similar to control charge/discharge paths.

Use Value: Low R_DS(on) minimizes voltage drop across protection FET, preserving usable battery capacity and runtime.

Use Scenario: High-efficiency buck converter output stage in point-of-load regulators for FPGA or ASIC core supplies.

IC Role / Device Role / Timing Role: Synchronous rectifier replacing Schottky diode to reduce conduction loss during low-side conduction phase.

Use Value: 15 mΩ R_DS(on) cuts forward voltage drop to ~150 mV at 10 A, improving conversion efficiency by 2–3% vs. diode solution.

Load Switch for Industrial PLC

Hot-Swap Controller Interface

Use Scenario: Controlled power-up of field I/O modules in programmable logic controllers with surge and short-circuit protection.

IC Role / Device Role / Timing Role: High-side switch isolating downstream loads; driven by isolated GPIO or dedicated load switch controller.

Use Value: Logic-level gate enables direct control from 3.3 V digital isolators; SO-8 footprint simplifies layout in space-constrained DIN-rail modules.

Use Scenario: Inrush current limiting and fault isolation in modular server backplanes with hot-plug capability.

IC Role / Device Role / Timing Role: Main pass element in discrete hot-swap circuit, paired with current-sense amplifier and comparator.

Use Value: Fast turn-off (t_f = 25 ns) and low Q_g support precise current-limit response and minimize fault energy during overcurrent events.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Si2305DDS	Lower I_D rating (-4.1 A), higher R_DS(on) (48 mΩ @ -4.5 V), SOT-23 package.	Suitable only for sub-2 A loads; limited thermal headroom in continuous operation.	Select Si2305DDS only when board space is critical and current demand is ≤3 A.
IRF7404PbF	Higher R_DS(on) (28 mΩ @ -4.5 V), same SO-8 package, slightly higher Q_g (42 nC).	Acceptable in lower-efficiency designs where cost is prioritized over thermal performance.	IRF7404PbF offers legacy supply chain continuity but sacrifices ~45% conduction loss vs. AO4409.

Compared with Si2305DDS and IRF7404PbF, the AO4409 delivers superior current handling and lower on-resistance in the same SO-8 footprint-making it optimal for 10–15 A high-side switching where thermal margin and efficiency are critical.

Availability

AO4409 is available at Aetrix Electronics and suitable for battery management systems, industrial PLC I/O modules, DC-DC synchronous rectifiers, and hot-swap controller interfaces requiring stable component supply and halogen-free compliance.

Supply support for AO4409 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 high-efficiency power conversion.

The AO4409 belongs to AOS's logic-level P-channel MOSFET product line, engineered for high-side switching in battery-powered and industrial power systems where low gate drive voltage and low R_DS(on) are essential.

FAQ

What is the maximum continuous drain current rating for AO4409?

The AO4409 is rated for -15 A continuous drain current at case temperature T_C = 25°C. This rating decreases with rising temperature-derating to approximately -9 A at T_C = 100°C per the Safe Operating Area (SOA) curve. For sustained operation above 5 A, PCB copper pour under the exposed drain pad is strongly recommended to maintain junction temperature within -55°C to +150°C limits. The AO4409 must be operated within its SOA boundaries to avoid thermal runaway.

Does AO4409 support logic-level gate drive?

Yes, the AO4409 supports logic-level gate drive with a gate threshold voltage (V_GS(th)) range of -1.0 V to -2.5 V and guaranteed R_DS(on) ≤ 22 mΩ at V_GS = -4.5 V. This allows direct interfacing with 3.3 V or 5 V microcontrollers, PMICs, and digital isolators without external level-shifting circuitry. The AO4409's low gate charge (34 nC) further ensures fast switching with minimal driver power consumption.

Is AO4409 halogen-free and RoHS compliant?

Yes, the AO4409 is manufactured per AOS Green Policy and is halogen-free (Br < 900 ppm, Cl < 900 ppm, total Br+Cl < 1500 ppm) and RoHS compliant. All SO-8 packaged AO4409 devices produced after 2010 meet these requirements, regardless of part number suffix. No "L" suffix is used for SO-8-only TO-220, TO-220F, TO-263, and TO-247 packages carry the "L" designation for green versions. The AO4409 qualifies for use in environmentally regulated markets including EU, Japan, and China.

What is the thermal resistance from junction to ambient for AO4409?

The AO4409 has a junction-to-ambient thermal resistance (R_θJA) of 50°C/W when mounted on a standard 1-in² FR-4 PCB with 1 oz copper. This value assumes no additional heatsinking. With a 2-in² copper pour connected to the exposed drain pad, R_θJA improves to ~35°C/W. The lower junction-to-case resistance (R_θJC = 2.5°C/W) confirms the effectiveness of the SO-8 exposed pad for thermal transfer. These values directly determine the maximum allowable power dissipation before exceeding the +150°C maximum junction temperature.

Can AO4409 be used as a high-side switch in a 12 V automotive system?

Yes, the AO4409 can be used as a high-side switch in 12 V automotive systems, provided transient voltage clamping is implemented. Its -30 V V_DS rating accommodates typical 12 V nominal systems but does not cover load-dump transients (up to +40 V). External TVS diodes or clamp circuits are required for ISO 7637-2 compliance. The AO4409's -55°C to +150°C operating range and halogen-free construction meet automotive-grade reliability expectations, though AEC-Q101 qualification is not claimed for this specific part.

AO4409 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:: P-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 30 V

Current - Continuous Drain (Id) @ 25°C:: 15A (Ta)

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

Rds On (Max) @ Id, Vgs:: 7.5mOhm @ 15A, 10V

Vgs(th) (Max) @ Id:: 2.7V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 120 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 6400 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

AO4409 FAQ

1.How can I place an order for AO4409 through Aetrix?

Please submit a Request for Quotation (RFQ) for AO4409 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 AO4409 reliable?

The price and inventory of AO4409 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AO4409 is usually 5 days.

3.What payment methods are accepted for AO4409?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AO4409 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AO4409?

AO4409 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AO4409 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 AO4409?

For technical support, including AO4409 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AO4409 requirements.

6.How does Aetrix verify that AO4409 is sourced from the original manufacturer or authorized distributors?

All AO4409 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 AO4409 meets industry standards.

7.What is the process for return or replacement of AO4409?

All AO4409 units undergo pre-shipment inspection (PSI). If there is an issue with AO4409, 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 AO4409 part is unused and in its original packaging.

Return procedure for AO4409:

1.Submit a request within 90 days.

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

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