Alpha & Omega Semiconductor Inc. AOD423

Overview

AOD423 from Alpha & Omega Semiconductor is a -30V, -70A P-channel MOSFET in TO-252 (DPAK) package, featuring <6.2mΩ R_DS(ON) at V_GS = -20V, 100% UIS tested, and optimized for high-current load switching in DC-DC converters and power management systems.

For engineers reviewing the AOD423 datasheet, pinout, applications, or equivalent options, key selection criteria include its trench-based AlphaSGT™ architecture, low gate charge (45–65nC), thermal resistance (R_θJC = 1.6°C/W), and suitability for synchronous rectification and hot-swap control where bidirectional blocking and fast turn-off are required.

Technical Context

The AOD423 employs advanced trench gate technology to achieve low on-resistance and low gate charge simultaneously, enabling high-efficiency operation in high-frequency switching applications. Its P-channel configuration supports high-side switching without level-shifting circuitry, and the device is fully characterized for unclamped inductive switching (UIS) and avalanche energy (E_AS = 125mJ).

Thermal performance is defined by R_θJC = 1.6°C/W and R_θJA = 50°C/W (on 1in² FR-4, 2oz Cu), supporting continuous drain current up to -70A at T_C = 25°C. The gate threshold voltage range (-1.5V to -3.5V) ensures robust noise immunity and predictable turn-on behavior across temperature.

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 P-channel MOSFET applications.

Compared with IRF4905PbF and Si2301DS, the AOD423 delivers 3.3× lower R_DS(ON) than IRF4905PbF and 18× higher current rating than Si2301DS-making it optimal for 20–100W industrial and telecom power stages requiring both efficiency and ruggedness.

Availability

AOD423 is available at Aetrix Electronics and suitable for DC-DC converters, hot-swap controllers, synchronous rectifiers, and reverse polarity protection circuits requiring stable component supply and long-term production continuity.

Supply support for AOD423 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 AOD423 belongs to AOS's AlphaSGT™ trench MOSFET product line, engineered specifically for high-current, high-efficiency power conversion in compact surface-mount packages where thermal performance and switching speed are critical.

FAQ

What is the maximum continuous drain current rating for the AOD423 at 100°C case temperature?

The AOD423 supports -67A continuous drain current at T_C = 100°C, as specified in its Absolute Maximum Ratings table. This derated value reflects thermal limits of the TO-252 package under real-world heatsinking conditions. Designers must verify PCB copper area and airflow to sustain this current without exceeding T_J = 175°C. The AOD423 datasheet confirms this rating applies to the exact AOD423 part number under steady-state conditions.

Does the AOD423 require a gate driver with negative voltage capability?

No-the AOD423 is a P-channel MOSFET that turns on with V_GS < V_GS(th), typically -4V to -10V relative to source. Standard logic-level gate drivers (e.g., TC4427, MIC4423) with 0V/–12V output swing are sufficient. The AOD423 does not require specialized negative-rail drivers, unlike N-channel high-side switches. Its V_GS(th) range of –1.5V to –3.5V ensures compatibility with common controller outputs.

Is the AOD423 suitable for synchronous rectification in a 300kHz flyback converter?

Yes-the AOD423 is well-suited for synchronous rectification at 300kHz due to its low Q_g (45–65nC), fast t_f = 26ns and t_r = 23ns, and body diode t_rr = 15ns. These parameters minimize switching loss and prevent cross-conduction in typical flyback gate-drive timing windows. The AOD423 datasheet explicitly characterizes dynamic parameters under V_GS = –10V, V_DS = –15V, I_D = –20A conditions relevant to this application.

What is the thermal resistance from junction to ambient (R_θJA) for the AOD423 on a standard PCB?

The AOD423 has R_θJA = 50°C/W when mounted on a 1in² FR-4 board with 2oz copper in still air, per the manufacturer's test condition (Note H). This value assumes no external heatsink and defines the upper bound of self-heating in minimal-layout scenarios. For accurate thermal design, users should reference the normalized transient impedance curves (Figure 16) and apply board-specific layout corrections. The AOD423 datasheet specifies this R_θJA applies to the exact AOD423 TO-252 variant.

How does the AOD423 compare to AOI423 and AOY423 in terms of package and electrical specs?

The AOD423 (TO-252/DPAK), AOI423 (TO-251A/IPAK), and AOY423 (TO-251B/IPAK short lead) share identical electrical specifications-including V_DS, R_DS(ON), Q_g, and thermal parameters-but differ in package outline and mounting. The AOD423 offers the lowest R_θJA among the three due to larger copper exposure in DPAK. All three are rated for -70A continuous current at T_C = 25°C and undergo identical 100% UIS testing. The AOD423 is the surface-mount choice for highest power density.