Alpha & Omega Semiconductor Inc. AO4482

Overview

AO4482 from Alpha & Omega Semiconductor is a 100V N-channel enhancement-mode MOSFET in SO-8 package, featuring R_DS(ON) < 37 mΩ at V_GS = 10 V and < 42 mΩ at V_GS = 4.5 V, 6 A continuous drain current, 100% UIS tested, and optimized for synchronous rectification in DC/DC converters.

For engineers reviewing the AO4482 datasheet, pinout, applications, or equivalent options, key selection criteria include its low R_DS(ON) at 4.5 V gate drive, SO-8 thermal performance (R_θJA = 75 °C/W), avalanche ruggedness (E_AS = 61 mJ), and suitability for high-efficiency boost converters and LED backlighting power stages.

Technical Context

The AO4482 uses advanced trench-gate MOSFET technology to achieve low on-resistance while maintaining fast switching characteristics: t_d(on) = 7 ns, t_r = 7 ns, t_d(off) = 28 ns, and t_f = 7 ns under standard test conditions (V_GS = 10 V, V_DS = 50 V, R_GEN = 3 Ω). Its gate charge profile shows Q_g(10V) = 36 nC typical and Q_g(4.5V) = 18 nC, supporting efficient 5 V logic-level drive.

Thermally, the device is rated for junction temperatures from –55 °C to +150 °C, with R_θJL = 2 °C/W and R_θJA = 75 °C/W (1 in² FR-4, 2 oz Cu). It undergoes 100% R_g and UIS testing per production lot, ensuring robustness in unclamped inductive switching applications such as synchronous buck output stages.

Key Specifications

Pinout & Package

AO4482 is housed in a surface-mount SO-8 package with exposed drain pad for enhanced thermal performance. The package supports standard reflow profiles and offers dual-side cooling capability when the drain pad is soldered to a thermal plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si2302DS-T1-GE3 and IRF7470PBF, the AO4482 delivers superior thermal performance via its exposed drain pad, tighter R_DS(ON) tolerance at 4.5 V, and production-tested UIS robustness-making it the preferred choice for 100 V synchronous rectifier designs requiring long-term reliability.

Availability

AO4482 is available at Aetrix Electronics and suitable for LED backlighting power stages, telecom DC/DC converters, and industrial AC/DC adapters requiring stable component supply, consistent parametric performance, and full traceability across production lots.

Supply support for AO4482 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-performance MOSFETs, IGBTs, and power modules for computing, consumer, industrial, and automotive markets.

The AO4482 belongs to AOS's TrenchMOS® family, engineered specifically for high-efficiency, high-frequency switching applications where low gate charge, low R_DS(ON), and rugged avalanche performance are essential.

FAQ

What is the maximum gate-source voltage rating for AO4482?

The AO4482 has a maximum gate-source voltage (V_GS) rating of ±20 V. Exceeding this limit risks permanent gate oxide damage. In practice, gate drive circuits should be designed to clamp V_GS within –10 V to +15 V to ensure long-term reliability. The AO4482 datasheet specifies that gate leakage (I_GSS) remains below 100 nA at ±20 V, confirming robust gate insulation integrity under rated stress.

Does AO4482 support 5 V logic-level gate drive?

Yes, the AO4482 supports 5 V logic-level gate drive: its gate threshold voltage (V_GS(th)) ranges from 1.6 V to 2.7 V, and R_DS(ON) is guaranteed < 42 mΩ at V_GS = 4.5 V with I_D = 5 A. This enables direct interface with 5 V microcontrollers, PWM controllers, and gate drivers without level-shifting circuitry-reducing bill-of-materials cost and layout complexity in compact power designs.

What is the body diode forward voltage of AO4482 at 1 A?

The body diode forward voltage (V_SD) of AO4482 is specified as 0.7 V minimum and 1.0 V maximum at I_S = 1 A and V_GS = 0 V. This low V_SD contributes to reduced conduction loss during dead-time conduction in synchronous rectifier topologies. At elevated temperatures (T_J = 125 °C), V_SD decreases slightly due to negative temperature coefficient of the intrinsic diode.

Is AO4482 suitable for synchronous rectification in LLC resonant converters?

Yes, AO4482 is suitable for synchronous rectification in LLC resonant converters. Its fast body diode recovery (t_rr = 25 ns typical, Q_rr = 130 nC) and low R_DS(ON) minimize both conduction and switching losses during zero-voltage switching transitions. The 100% UIS testing further ensures resilience against the high dI/dt and voltage overshoots common during LLC transient events.

What thermal resistance values apply to AO4482 in standard PCB mounting?

For AO4482 mounted on a 1 in² FR-4 board with 2 oz copper, the datasheet specifies R_θJA = 75 °C/W (steady-state) and R_θJL = 2 °C/W (junction-to-lead). These values assume the exposed drain pad is fully soldered to a thermal plane. Without thermal pad connection, R_θJA degrades significantly-designers must verify thermal relief patterns and solder coverage to maintain rated power dissipation of 3.1 W at T_A = 70 °C.