Alpha & Omega Semiconductor Inc. AO4286

Overview

AO4286 from Alpha & Omega Semiconductor is a 100V N-Channel Trench MOSFET optimized for high-frequency switching, with R_DS(ON) < 68 mΩ at V_GS = 10 V, 4 A continuous drain current, and 100% UIS tested. It serves as a synchronous rectifier or high-side/low-side switch in DC-DC converters.

For engineers reviewing the AO4286 datasheet, pinout, applications, or equivalent options, key selection criteria include its SOIC-8 package thermal resistance (R_θJA = 85 °C/W), gate charge (Q_g = 5.8–10 nC at 10 V), body diode recovery (Q_rr = 53 nC), and avalanche ruggedness (E_AS = 0.8 mJ).

Technical Context

The AO4286 employs trench-gate silicon technology to minimize conduction loss (R_DS(ON)) and switching loss (C_iss = 390 pF, C_oss = 30 pF) simultaneously. Its low Q_gd/Q_g ratio (1.2/5.8 nC) supports fast, controllable turn-off critical for ZVS and resonant topologies.

Designed for operation up to 150 °C junction temperature, it features a gate threshold voltage of 1.7–2.9 V and is characterized across temperature for stable R_DS(ON) behavior - increasing only ~1.8× from 25 °C to 125 °C at V_GS = 10 V.

Key Specifications

Pinout & Package

AO4286 is housed in a surface-mount SOIC-8 package with exposed drain pads on pins 1–4 and 6–8, source on pins 5 and 7, and gate on pin 3 - enabling dual-drain paralleling and low-inductance layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si2302DS-T1-E3 and IRF7470PBF, the AO4286 delivers optimal balance of 100 V rating, UIS ruggedness, and gate-drive efficiency - making it uniquely suited for unclamped, medium-power switching where reliability and thermal margin are critical.

Availability

AO4286 is available at Aetrix Electronics and suitable for LED backlighting, telecom power adapters, and industrial 48 V DC-DC converters requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AO4286 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 ICs for computing, consumer, and industrial markets.

The AO4286 belongs to AOS's TrenchMOS® family, engineered specifically for high-frequency, high-reliability power conversion where low gate charge, avalanche robustness, and thermal performance are essential.

FAQ

What is the maximum continuous drain current rating for AO4286 at 70°C case temperature?

The AO4286 supports 3 A continuous drain current at T_C = 70 °C, as specified in its Absolute Maximum Ratings table. This derating reflects thermal limits under real-world PCB mounting conditions and ensures safe operation without exceeding the 150 °C maximum junction temperature. The AO4286 maintains this rating while retaining low R_DS(ON) and fast switching behavior critical for high-efficiency designs.

Does AO4286 support 4.5 V gate drive in practical applications?

Yes, the AO4286 is fully characterized at V_GS = 4.5 V, with R_DS(ON) < 92 mΩ and I_D = 3 A. Its gate threshold voltage range (1.7–2.9 V) ensures reliable turn-on with standard 3.3 V or 5 V logic-level drivers. The AO4286 delivers usable conduction performance in 5 V-controlled buck converters and battery-powered systems where 10 V gate drive is unavailable.

How does the body diode performance of AO4286 impact synchronous rectification efficiency?

The AO4286 body diode exhibits t_rr = 15 ns and Q_rr = 53 nC, enabling fast, low-loss commutation in synchronous rectifiers. These values directly reduce dead-time conduction loss and minimize voltage spikes during reverse recovery - a key factor in maintaining >94% efficiency in 300–600 kHz DC-DC stages. The AO4286's consistent diode behavior across temperature further stabilizes light-load performance.

Is AO4286 suitable for use in automotive infotainment power supplies?

The AO4286 is not AEC-Q101 qualified and is intended for commercial/industrial applications only. While its 100 V rating and thermal robustness suit 48 V bus-derived subsystems, Aetrix Electronics does not recommend AO4286 for automotive safety-critical or mission-critical infotainment power supplies without additional qualification testing. For such applications, consider AOS's AUIRF series or other AEC-Q101-compliant alternatives instead of AO4286.

What is the thermal resistance from junction to ambient (R_θJA) for AO4286 on a standard PCB?

The AO4286 has an R_θJA of 85 °C/W when mounted on a 1 in² FR-4 board with 2 oz copper in still air - per JEDEC JESD51-7 test conditions. This value assumes no external heatsink and defines the baseline for thermal design. In practice, adding copper pour or thermal vias beneath the drain pads can reduce effective R_θJA by 15–25%, allowing higher sustained power in the AO4286 without exceeding 150 °C junction temperature.