AO4409 MOSFET — Specifications & Equivalents
Manufacturer: Commonly produced by Alpha & Omega Semiconductor
About the AO4409
The AO4409 is a P-channel MOSFET with a drain–source voltage (VDS) rating of 30 V, a continuous drain current (ID) of 15 A and an on-resistance (RDS(on)) of 0.0075 Ω. It can dissipate up to 3.1 W and is rated to a junction temperature of 150 °C. It is supplied in the SO-8 package.
At a glance
- Type: P-channel MOSFET
- Max drain–source voltage (VDS): 30 V
- Max continuous drain current (ID): 15 A
- On-resistance (RDS(on)): 0.0075 Ω
- Power dissipation (PD): 3.1 W
- Max junction temperature (TJ): 150 °C
- Package: SO-8
- Manufacturer: Commonly produced by Alpha & Omega Semiconductor
Typical applications
With its 30 V drain–source rating the AO4409 sits in the low-voltage class of switching MOSFETs, typically found in 12 V and 24 V automotive and industrial rails, synchronous buck converters, load switching and reverse-polarity protection and H-bridges for small motors.
The low 0.0075 Ω on-resistance keeps conduction loss down, which suits synchronous rectification and continuous high-current paths.
Gate drive and switching notes
Keep gate–source voltage within the ±20 V maximum; exceeding it punctures the gate oxide and destroys the device permanently.
Switching behaviour is characterised by a rise time of 16.5 ns and an output capacitance (Coss) of 945 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.
Choosing a replacement for the AO4409
A drop-in substitute for the AO4409 must be the same P-channel type and offer a drain–source rating of at least 30 V, a continuous drain current rating of at least 15 A and an on-resistance no higher than 0.0075 Ω if efficiency and heat matter.
Mechanically, check the replacement against the SO-8 footprint and confirm the pin order — parts sharing a package outline do not always share a pinout.
Where the application switches inductive loads or runs near the voltage limit, keep extra headroom rather than choosing a part that only just meets the original numbers.
Frequently asked questions
What is the AO4409?
The AO4409 is a P-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 30 V drain-source and 15 A continuous drain current.
What is the maximum voltage of the AO4409?
The AO4409 has a maximum drain-source voltage (Vds) of 30 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.
How much current can the AO4409 handle?
It is rated for 15 A of continuous drain current, with power dissipation limited to 3.1 W. Real-world capability depends on your heatsinking and ambient temperature.
What is the on-resistance of the AO4409?
On-resistance (Rds(on)) is 0.0075 Ω. Multiply by the square of your load current to estimate conduction loss.
What package does the AO4409 come in?
It is listed in SO-8. Verify the pinout of the specific variant, as one outline can carry different pin assignments.
What can I use to replace the AO4409?
No verified equivalents are listed yet. Choose a part of the same polarity that meets or exceeds every rating above and shares a compatible package and pinout.
Key Specifications
| Type | MOSFET |
|---|---|
| Channel Type | P -Channel |
| Drain-Source Voltage (Vds) | 30 V |
| Gate-Source Voltage (Vgs) | 20 V |
| Drain Current (Id) | 15 A |
| Drain-Source On-Resistance (Rds) | 0.0075 |
| Rise Time (tr) | 16.5 nS |
| Output Capacitance (Coss) | 945 pF |
| Junction Temperature (Tj) | 150 °C |
| Package | SO-8 |
| Power Dissipation (Pd) | 3.1 W |
Equivalent & Replacement Parts
No verified equivalents are listed for AO4409 yet.