Alpha & Omega Semiconductor Inc. AOD256

Overview

AOD256 from Alpha & Omega Semiconductor is a 150V, 19A N-Channel Trench MOSFET in TO-252 (DPAK) package, optimized for high-frequency switching with R_DS(ON) < 85 mΩ at V_GS = 10 V and C_iss = 1165 pF. It delivers low conduction and switching losses in boost converters and synchronous rectifiers for telecom and industrial power supplies.

For engineers reviewing the AOD256 datasheet, pinout, applications, or equivalent options, key selection criteria include its 100% UIS-tested ruggedness, gate charge of 22 nC (at 10 V), body diode reverse recovery time of 37 ns, and thermal resistance R_θJC = 1.8 °C/W - critical for compact, high-efficiency DC-DC designs.

Technical Context

The AOD256 employs trench-gate MOSFET architecture to simultaneously minimize R_DS(ON), input capacitance (C_iss = 1165 pF), and output capacitance (C_oss = 61.5 pF), enabling fast switching with reduced energy loss per transition. Its gate threshold voltage (1.8–2.8 V) supports 4.5 V logic-level drive while maintaining robust noise immunity.

Rated for 175 °C maximum junction temperature and 100% avalanche tested (E_AS = 139 mJ), the AOD256 sustains repetitive unclamped inductive switching stress without degradation. The device's low Q_gd/Q_g ratio (1.2 nC / 22 nC) improves hard-switching stability and reduces Miller-induced shoot-through risk.

Key Specifications

Pinout & Package

Package: TO-252 (DPAK), surface-mount, thermally enhanced with exposed drain pad on bottom side.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP16NF15 and IRF6616, the AOD256 uniquely balances 150 V rating, 19 A current capability, sub-85 mΩ on-resistance, and guaranteed UIS performance - making it the only option among the three qualified for rugged, high-frequency boost and synchronous rectifier use at full 150 V stress.

Availability

AOD256 is available at Aetrix Electronics and suitable for boost converters, synchronous rectifiers, industrial power supplies, and telecom DC-DC modules requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AOD256 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 telecom markets.

The AOD256 belongs to AOS's TrenchMOS® family, engineered specifically for high-efficiency, high-frequency DC-DC conversion where low R_DS(ON) × Q_g and rugged avalanche capability are mandatory.

FAQ

What is the maximum continuous drain current for the AOD256 at 70°C ambient temperature?

The AOD256 supports 13.5 A continuous drain current at T_A = 70°C with standard PCB mounting (1 in² FR-4, 2 oz. copper). This rating derives from its R_θJA = 50 °C/W and maximum junction temperature of 175 °C. At higher board copper area or with heatsinking, current capacity increases - for example, at T_C = 25°C, the AOD256 handles 19 A continuously. Always verify thermal design using actual layout and airflow conditions before finalizing the AOD256 in your application.

Does the AOD256 support 4.5 V logic-level gate drive?

Yes, the AOD256 is fully compatible with 4.5 V gate drive: its R_DS(ON) remains < 100 mΩ at V_GS = 4.5 V, and gate threshold voltage is specified from 1.8 V to 2.8 V. With Q_g(4.5 V) = 7–10 nC, it can be driven cleanly by standard 3.3 V or 5 V microcontrollers and gate drivers without level-shifting. This makes the AOD256 suitable for low-voltage control architectures in modern telecom and industrial power systems where the AOD256 replaces higher-threshold MOSFETs.

Is the AOD256 rated for avalanche operation, and what is its E_AS value?

Yes, the AOD256 is 100% tested for unclamped inductive switching (UIS) with a guaranteed single-pulse avalanche energy rating of 139 mJ at T_J = 25°C. This specification ensures robustness against voltage spikes caused by transformer leakage inductance or cable inductance during turn-off. Unlike non-rated MOSFETs, the AOD256 does not require external clamping circuits in most flyback or forward converter designs - a key reliability advantage confirmed in AOS' official datasheet Rev 1.1.

What is the thermal resistance from junction to case (R_θJC) for the AOD256, and how is it used in thermal design?

The AOD256 has R_θJC = 1.8 °C/W, measured from junction to the exposed drain pad on the TO-252 package bottom. This value is used when the device is mounted to a heatsink or large copper area - enabling calculation of junction temperature as T_J = T_C + P_D × R_θJC. For example, at 41.5 W dissipation and T_C = 25°C, T_J = 100°C, well below the 175°C limit. Accurate thermal modeling of the AOD256 requires including interface material resistance and heatsink thermal impedance in the full path.

Can the AOD256 be used as a synchronous rectifier, and what body diode parameters support this?

Yes, the AOD256 is qualified for synchronous rectification: its body diode exhibits V_SD = 0.72 V (typical) at I_S = 1 A and reverse recovery time t_rr = 37 ns at I_F = 10 A, dI/dt = 500 A/μs. These values enable efficient replacement of Schottky diodes in secondary-side circuits up to 300 kHz, reducing conduction loss and eliminating reverse recovery loss. The AOD256's low Q_rr (265 nC) further minimizes switching loss during commutation - a verified capability documented in the AOD256 datasheet's dynamic parameter table.