Alpha & Omega Semiconductor Inc. AOH3106

Overview

AOH3106 from Alpha & Omega Semiconductor is a 100V N-Channel enhancement-mode trench MOSFET in SOT-223 package, rated for 2A continuous drain current at V_GS=10V, with R_DS(ON) < 360 mΩ at V_GS=10V and < 385 mΩ at V_GS=4.5V. It serves as a high-efficiency synchronous rectifier or boost switch in low-voltage DC-DC converters for LED backlighting and telecom power supplies.

For engineers reviewing the AOH3106 datasheet, pinout, applications, or equivalent options, key selection criteria include its 100V V_DS, low gate charge (Q_g=4.8–10 nC), fast switching (t_on≈3.5 ns, t_off≈16 ns), body diode recovery performance (t_rr=17 ns, Q_rr=14.5 nC), and thermal resistance (R_θJA=75°C/W).

Technical Context

The AOH3106 employs advanced trench-gate silicon process to achieve low R_DS(ON) while maintaining robust avalanche capability (E_AS=1.3 mJ) and stable threshold voltage (V_GS(th)=1.0–2.0 V). Its dynamic parameters-including C_iss=185 pF, C_oss=19 pF, and Cr_ss=8 pF-are optimized for high-frequency switching in isolated and non-isolated topologies.

Thermally, it uses a low-R_θJL (1.3°C/W) lead-frame structure enabling efficient heat transfer from junction to lead, and supports operation across –55°C to +150°C junction temperature range. The device is characterized for both steady-state and pulsed conditions, with ID_M=7 A and P_D=3.1 W at T_A=25°C.

Key Specifications

Pinout & Package

SOT-223 package with exposed drain pad for thermal and electrical connection; standardized 3-pin configuration with G–D–S terminal order on top view (G=Gate, D=Drain, S=Source).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AO3400 and SI2302DS, the AOH3106 uniquely combines 100 V rating, SOT-223 thermal capability, and sub-400 mΩ R_DS(ON) at 4.5 V gate drive-making it the only viable option among the three for 48 V-input boost and telecom rectification.

Availability

AOH3106 is available at Aetrix Electronics and suitable for LED backlighting, telecom DC-DC converters, and industrial AC-DC adapters requiring stable component supply and long-term production continuity.

Supply support for AOH3106 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 ICs for computing, consumer, industrial, and automotive markets.

The AOH3106 belongs to AOS's "AOH" series of low-R_DS(ON) discrete MOSFETs designed specifically for space-constrained, high-efficiency power conversion in consumer and telecom infrastructure.

FAQ

What is the maximum continuous drain current for the AOH3106 at 70°C ambient temperature?

The AOH3106 supports 1.5 A continuous drain current at T_A=70°C per its Absolute Maximum Ratings table. This derating reflects thermal limits imposed by R_θJA=75°C/W and T_J(MAX)=150°C. At board-level conditions matching the datasheet test setup (1-in² FR-4, 2 oz Cu), the AOH3106 maintains safe operation up to this current without exceeding junction temperature limits.

Does the AOH3106 have avalanche energy rating, and how is it specified?

Yes, the AOH3106 has a rated single-pulse avalanche energy (E_AS) of 1.3 mJ, measured under standardized test conditions (I_AS=5 A, L=100 µH, V_DD=100 V). This specification confirms ruggedness against inductive switching stress in hard-switched topologies and validates reliability in unclamped inductive load scenarios without external protection.

Can the AOH3106 be driven directly from a 3.3 V microcontroller GPIO?

The AOH3106 can be partially enhanced at 3.3 V due to its V_GS(th) range of 1.0–2.0 V, but R_DS(ON) will be significantly higher than rated-typically >1 Ω-leading to excessive conduction loss. For reliable 2 A operation, ≥4.5 V gate drive is required. A level-shifting driver or dedicated gate driver IC is recommended for full performance.

What is the thermal resistance from junction to lead (R_θJL) for the AOH3106, and why does it matter?

The AOH3106 has R_θJL=1.3°C/W, measured from junction to the exposed drain pad. This low value enables efficient heat transfer to an external heatsink or large copper pour, especially critical in SOT-223 packages where the drain pad is the primary thermal path. It directly impacts achievable power density and long-term reliability in thermally constrained layouts.

Is the AOH3106 suitable for use as a synchronous rectifier in a 500 kHz flyback converter?

Yes, the AOH3106 is suitable for 500 kHz flyback synchronous rectification due to its fast switching (t_on≈3.5 ns, t_off≈16 ns), low Q_g, and well-characterized body diode recovery (t_rr=17 ns, Q_rr=14.5 nC). These parameters reduce dead-time losses and EMI generation, provided gate drive timing is precisely matched to the controller's SR signal.