Loading…
SOT-23 · AO3400
ActiveN-Channel MOSFET (30V/5.7A)
AO3400
Alpha & Omega Semiconductor · SOT-23 · N-Channel MOSFET (30V/5.7A)
Price on Request
Get a competitive quote within 24 hours. Volume discounts available. Shenzhen stock ships in 1-2 business days.
Overview
The AO3400 (current AO3400A revision) is Alpha & Omega Semiconductor's workhorse 30V N-channel trench MOSFET in the SOT-23 package, and it is one of the highest-volume small-signal power switches on the market. It pairs a 5.7A continuous drain current at TA = 25°C (4.7A at TA = 70°C) with an on-resistance below 26.5mΩ at VGS = 10V and below 32mΩ at VGS = 4.5V, so a 3.3V or 5V logic rail drives it fully on without a gate driver.
The gate threshold of 0.65V to 1.45V and a total gate charge of only 7nC make it ideal for high-frequency PWM: turn-on delay is about 3ns and turn-off about 25ns into a 2.6Ω load. Input capacitance is 630pF and the body diode recovers in 8.5ns with 2.6nC of charge, which keeps switching loss and shoot-through risk low in synchronous buck and load-switch circuits. Power dissipation is 1.4W at TA = 25°C on a 1in² 2oz copper pad, and the junction is rated from -55°C to +150°C.
Because the part is so popular, second sources abound: onsemi, Diodes Inc, Nexperia, Toshiba and many Shenzhen vendors sell pin-compatible SOT-23 30V parts, but RDS(on), gate charge and thermal data differ. For BOM stability specify the exact AOS part number. Beware remarked 20V parts sold as AO3400; verify VDS breakdown and RDS(on) at 4.5V on incoming inspection. Shenzhen stock is deep, MOQ typically 3,000 pcs per reel.
Key Features
- 30V / 5.7A N-channel trench MOSFET in SOT-23
- Logic-level: RDS(on) < 32mΩ at VGS = 4.5V
- Low gate charge 7nC for efficient PWM
- 1.4W dissipation at TA = 25°C
- Fast body diode: 8.5ns reverse recovery
Typical Applications
- Load switching and power gating in portable products
- Synchronous buck converters and POL regulators
- Battery protection and charge-path switching
- Level shifting between 1.8V, 3.3V and 5V domains
- LED and small motor PWM drivers
- I2C/SPI bus isolation and signal muxing
Specifications
- Channel Type
- N-Channel
- Drain-Source Voltage (VDS)
- 30 V
- Continuous Drain Current (ID, TA = 25 °C)
- 5.7 A
- RDS(on) max (VGS = 10 V, ID = 5.7 A)
- 26.5 mΩ
- RDS(on) max (VGS = 4.5 V, ID = 5 A)
- 32 mΩ
- Gate Threshold Voltage VGS(th)
- 0.65 to 1.45 V
- Total Gate Charge (Qg) max
- 7 nC
- Power Dissipation (PD, TA = 25 °C)
- 1.4 W
- Pins
- 3
- RoHS
- Compliant
Procurement Tips
Put the full AOS ordering code (AO3400A) on your BOM rather than the generic AO3400, so the assembler cannot substitute a higher-RDS(on) clone; request reel photos and a sample RDS(on) report before volume release.
Frequently Asked Questions
AO3400 vs AO3400A - are they the same part?
AO3400A is the current, improved revision of AO3400 with the same SOT-23 pinout and 30V rating. The A revision tightens RDS(on) (26.5mΩ max at 10V) and raises the gate rating to ±12V. For new designs order AO3400A; older AO3400 stock is functionally interchangeable in most circuits.
AO3400 vs SI2302 - which is better?
SI2302 is a 20V part with about 60-90mΩ RDS(on); AO3400 is 30V with under 32mΩ at 4.5V and 5.7A continuous. AO3400 wins on both voltage headroom and on-resistance at similar price, so it has largely displaced SI2302 in load-switch designs. Keep SI2302 only where its specific sourcing or qualification history is required.
Can I drive AO3400 directly from a 3.3V MCU pin?
Yes. RDS(on) is specified at VGS = 4.5V and 2.5V (48mΩ max), and threshold is 0.65-1.45V, so 3.3V gives comfortable overdrive for currents up to a few amps. Add a 10-100Ω series gate resistor and a 100kΩ pulldown to keep the gate defined during MCU reset.
How much power can the SOT-23 package really dissipate?
The 1.4W figure assumes TA = 25°C on a 1in² 2oz copper pad using the short-pulse thermal resistance. In steady state on a small board expect closer to 0.9-1.0W. At 3A and 32mΩ you dissipate about 0.3W, which is comfortable; above 4A continuous you should move to a larger package.
Is AO3400 counterfeit-prone?
Moderately. Because many vendors make pin-compatible 30V SOT-23 MOSFETs, mislabeled or lower-spec parts appear in broker stock. Verify by measuring RDS(on) at VGS = 4.5V (genuine reads under 32mΩ) and checking breakdown above 30V. We source AOS-branded reels from authorized distribution and sample-test each lot.
What is the MOQ and lead time?
MOQ is 1 reel (3,000 pcs) for tape-and-reel SOT-23, or 100 pcs cut tape for prototypes. Shenzhen stock ships in 1-2 days; AOS authorized-channel replenishment is 6-10 weeks.
Alternatives & Equivalents
View full cross-reference table →Need AO3400 pricing and availability?
Submit an RFQ — we reply within 24 hours with stock, pricing, lead time and packaging options.
Request a Quote →