Alpha & Omega Semiconductor Inc. AO3400

Overview

AO3400 from Alpha & Omega Semiconductor is a 30V N-channel enhancement-mode trench MOSFET in SOT-23 package, rated for 5.8A continuous drain current at V_GS=10V, with R_DS(ON) < 28mΩ (V_GS=10V) and < 33mΩ (V_GS=4.5V). It serves as a low-loss load switch or PWM power stage in DC-DC converters and battery protection circuits.

For engineers reviewing the AO3400 datasheet, pinout, applications, or equivalent options, key selection criteria include its 30V V_DS, sub-33mΩ on-resistance at 4.5V gate drive, 1.05V typical gate threshold, 6nC total gate charge, and SOT-23 thermal performance with R_θJA = 125°C/W.

Technical Context

The AO3400 uses advanced trench-gate process to achieve low R_DS(ON) while maintaining fast switching: t_D(on) = 3ns, t_r = 2.5ns, Q_g = 6nC, and C_iss = 630pF at V_DS = 15V. Its body diode exhibits t_rr = 8.5ns and Q_rr = 2.6nC under IF = 5.8A, dI/dt = 100A/µs conditions.

Designed for single-ended low-side switching, the AO3400 operates with gate drive voltages down to 2.5V (R_DS(ON) < 52mΩ), supports pulsed drain currents up to 30A, and maintains safe operating area (SOA) compliance up to 10ms at 5A/10V with T_J ≤ 150°C.

Key Specifications

Pinout & Package

SOT-23 surface-mount package with gull-wing leads; compact 2.9mm × 1.3mm footprint and 1.0mm height; thermally enhanced leadframe design improves junction-to-lead transfer (R_θJL = 1.4°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with DMN3025LSD-13 and SI2300DS-T1-GE3, the AO3400 offers best-in-class balance of 4.5V R_DS(ON), gate charge, and threshold stability-making it optimal for space-constrained, logic-driven load switching where both efficiency and controllability matter.

Availability

AO3400 is available at Aetrix Electronics and suitable for battery protection circuits, USB power switches, and DC-DC synchronous rectifiers requiring stable component supply and consistent parametric performance across production lots.

Supply support for AO3400 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 high-efficiency MOSFETs, IGBTs, and power modules for consumer, computing, and industrial markets.

The AO3400 belongs to AOS's logic-level N-channel MOSFET product line, engineered specifically for compact, low-voltage power management applications where gate drive simplicity and thermal efficiency are critical.

FAQ

What is the maximum continuous drain current for AO3400 at 70°C ambient temperature?

The AO3400 supports 4.9A continuous drain current at T_A = 70°C with no heatsink, based on its 125°C/W junction-to-ambient thermal resistance and 150°C maximum junction temperature. This derating reflects real-world PCB thermal limitations and ensures reliable operation in enclosed consumer enclosures where airflow is restricted. The AO3400 datasheet specifies this value explicitly in the Absolute Maximum Ratings table.

Does AO3400 support 3.3V microcontroller GPIO direct drive without a level shifter?

Yes, the AO3400 supports direct drive from 3.3V GPIO because its R_DS(ON) remains below 52mΩ at V_GS = 2.5V and improves to <33mΩ at V_GS = 4.5V. With a typical V_GS(th) of 1.05V and max of 1.45V, the AO3400 fully enhances well within 3.3V logic swing, eliminating need for external level translation in most load-switching applications.

What is the safe operating area (SOA) limitation for AO3400 in single-pulse conditions?

The AO3400 SOA curve (Figure 9) permits 5A at 10V for 10ms pulses and 2A at 20V for 100ms pulses, all bounded by R_DS(ON) and thermal limits. At T_A = 25°C, the device can sustain 10A at 5V for 1ms without exceeding T_J = 150°C. These boundaries are validated per JEDEC JESD24-1 and apply only to single-pulse testing with proper gate drive and layout.

Is AO3400 suitable for use in automotive applications?

No, the AO3400 is explicitly qualified only for the consumer market per its datasheet disclaimer. It is not AEC-Q101 qualified, lacks automotive-grade screening, and has no guaranteed operation beyond −40°C to +85°C ambient. For automotive use, AOS recommends alternatives like AON6254 or AOB466, which undergo full AEC-Q101 stress testing and extended temperature validation. The AO3400 should not be deployed in safety-critical or engine-bay environments.

How does the body diode performance of AO3400 compare to discrete Schottky diodes in flyback designs?

The AO3400 body diode delivers t_rr = 8.5ns and Q_rr = 2.6nC at I_F = 5.8A, enabling efficient synchronous rectification without external diodes in low-power flybacks. While discrete Schottky diodes offer lower forward voltage, the AO3400 integrates conduction and recovery into one die, reducing board area and parasitic inductance. Its V_SD = 0.7–1.0V at 1A is higher than Schottky, but combined gate control and recovery predictability make it preferable in tightly timed, low-noise designs where the AO3400 replaces both switch and diode.