Alpha & Omega Semiconductor Inc. AON2420

Overview

AON2420 from Alpha & Omega Semiconductor is a 30V N-Channel enhancement-mode MOSFET in DFN 2×2B package, featuring R_DS(ON) < 11.7 mΩ at V_GS = 10 V and < 17.5 mΩ at V_GS = 4.5 V, 8 A continuous drain current, and low gate charge (Q_g(10V) = 12 nC), optimized for high-efficiency DC/DC converters in computing and telecom POL applications.

For engineers reviewing the AON2420 datasheet, pinout, applications, or equivalent options, key selection considerations include its 4.5V logic-level drive capability, thermal resistance (R_θJA = 80°C/W on 1-in² FR-4), body diode recovery performance (t_rr = 13.2 ns, Q_rr = 3.2 nC), and DFN 2×2B footprint compatibility with space-constrained power stages.

Technical Context

The AON2420 employs AlphaMOS LV trench technology to achieve low R_DS(ON) at both 10 V and 4.5 V gate drive, enabling efficient operation in synchronous buck converters where gate drive voltage may be limited by bootstrap or controller output. Its low Q_g(4.5V) = 5.8 nC and fast switching (t_D(on) = 4.8 ns, t_f = 4.0 ns) reduce switching losses in high-frequency (>500 kHz) power stages.

Thermally, the device uses a bottom-exposed DFN 2×2B package with direct die-to-PCB thermal path; R_θJC is not separately specified, but R_θJA = 80°C/W (1-in² FR-4, 2 oz Cu) supports up to 6 W steady-state dissipation at T_A = 25°C. The body diode exhibits V_SD = 1.0 V (typ) at I_S = 3.5 A and fast reverse recovery critical for synchronous rectification.

Key Specifications

Pinout & Package

Package: DFN 2×2B (2 mm × 2 mm, 0.75 mm height), bottom-exposed thermal pad, RoHS and halogen-free compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BSC014N04LS6 and SiA447DJ, the AON2420 delivers optimal balance of low 4.5 V R_DS(ON), compact DFN 2×2B footprint, and proven thermal performance on standard FR-4-making it preferred for space-constrained, high-frequency 8 A POL designs where gate drive voltage is limited to 4.5–5 V.

Availability

AON2420 is available at Aetrix Electronics and suitable for server point-of-load converters, telecom isolated DC/DC modules, and industrial motor drive gate drivers requiring stable component supply and consistent parametric performance across production lots.

Supply support for AON2420 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 AON2420 belongs to AOS' AlphaMOS LV trench MOSFET product line, engineered specifically for high-efficiency, high-frequency DC/DC conversion where low gate charge and 4.5 V logic-level drive are essential.

FAQ

What is the maximum continuous drain current rating for the AON2420 at 100°C ambient temperature?

The AON2420 supports 3.5 A continuous drain current at T_A = 100°C (derated from 8 A at 25°C), based on its R_θJA = 80°C/W and maximum junction temperature of 150°C. This rating assumes mounting on a 1-in² FR-4 board with 2 oz copper and still-air conditions. For higher current at elevated ambient, forced airflow or enhanced thermal pads are required. The AON2420 datasheet specifies this limit in the Absolute Maximum Ratings table under "Continuous Drain Current G".

Does the AON2420 have a specified avalanche energy rating (UIS)?

The AON2420 datasheet does not publish a rated unclamped inductive switching (UIS) energy (E_AS) value. While the device can withstand single-pulse inductive transients per its SOA curve (Figure 9), AOS does not guarantee or specify repetitive avalanche capability. Designers must ensure external clamping or snubbing circuits protect the AON2420 in inductive switching applications. This limitation applies to all variants in the AON2420 family per Rev1.0 datasheet.

Can the AON2420 be used as a replacement for the AON2405 in an existing design?

The AON2420 is not a direct replacement for the AON2405: although both are DFN 2×2B N-channel MOSFETs, the AON2405 has V_DS = 20 V and R_DS(ON) = 15.5 mΩ @ 4.5 V, while the AON2420 is rated for 30 V and achieves 17.5 mΩ @ 4.5 V. Substituting AON2420 into a 20 V system risks over-spec'ing voltage rating and may alter gate drive timing due to differing Q_g. Verify layout, thermal, and transient margins before using AON2420 in place of AON2405.

What is the gate threshold voltage range for the AON2420, and how does it affect turn-on behavior?

The AON2420 has a gate threshold voltage (V_GS(th)) range of 1.2 V to 2.2 V (typical 1.8 V) at T_J = 25°C. This low threshold enables reliable turn-on with 2.5–3.3 V logic signals, but designers must ensure gate drive exceeds 3× V_GS(th) (≥ 4.5 V) to achieve specified R_DS(ON). Below 4.5 V, the AON2420 operates in linear region with higher conduction loss-critical for accurate modeling in SPICE simulations of the AON2420.

Is the thermal pad on the bottom of the AON2420 DFN package electrically connected, and what is its function?

Yes, the exposed thermal pad on the underside of the AON2420 DFN 2×2B package is electrically connected to the source (S) terminal. Its primary function is thermal conduction-transferring heat from the silicon die directly to the PCB ground plane-while also providing mechanical stability and low-inductance source connection. Proper solder stencil design and 90%+ solder coverage are required to achieve the published R_θJA = 80°C/W. The AON2420 datasheet confirms this in the "Package Outline" and "Thermal Characteristics" sections.