Alpha & Omega Semiconductor Inc. AO4724

Overview

AO4724 from Alpha & Omega Semiconductor is a dual N-channel MOSFET in SO-8 package, rated for 30 V V_DS, 12 A continuous drain current per channel, and 22 mΩ typical R_DS(on) at V_GS = 10 V. It serves as a synchronous buck converter high-side/low-side switch in DC-DC power stages for notebook CPU core voltage regulation.

For engineers reviewing the AO4724 datasheet, pinout, applications, or equivalent options, key selection criteria include channel matching (ΔR_DS(on) ≤ 5%), low gate charge (Q_g = 19 nC), thermal resistance (R_θJA = 50 °C/W), and RoHS-compliant halogen-free packaging.

Technical Context

The AO4724 integrates two matched N-channel enhancement-mode MOSFETs in a single SO-8 thermally enhanced package. Its design targets high-frequency switching (up to 1 MHz) with fast turn-on (t_on = 12 ns) and turn-off (t_off = 22 ns) times under 10 V gate drive, enabling efficient synchronous rectification in point-of-load converters.

Each channel features a 100% UIS-rated avalanche energy capability (E_AS = 42 mJ), integrated body diode with reverse recovery time t_rr = 25 ns, and gate threshold voltage V_GS(th) = 1.7 V (min) to ensure robust TTL/CMOS-level drive compatibility.

Key Specifications

Pinout & Package

SO-8 package with exposed thermal pad (pin 8 connected to source of Q2); 4.9 mm × 6.0 mm footprint, 1.75 mm height, JEDEC MS-012AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si7850DP-T1-GE3 and IRF7341TRPBF, the AO4724 delivers optimal trade-off between R_DS(on), Q_g, and thermal resistance for 30 V synchronous buck converters operating above 500 kHz with tight layout constraints.

Availability

AO4724 is available at Aetrix Electronics and suitable for notebook VRMs, GPU power supplies, and industrial FPGA core rails requiring stable component supply, long-term lifecycle support, and halogen-free compliance.

Supply support for AO4724 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-efficiency MOSFETs, IGBTs, and power modules for computing, consumer, and industrial markets.

The AO4724 belongs to AOS's "AlphaMOS" dual-MOSFET product line, engineered specifically for high-density, high-frequency DC-DC conversion in portable and embedded systems.

FAQ

What is the maximum junction temperature rating for the AO4724?

The AO4724 has a maximum rated junction temperature of 150 °C. This rating is validated under steady-state thermal conditions with proper PCB copper pour on the thermal pad (pin 8) and ambient temperatures up to 85 °C. Derating is required above 85 °C ambient; the device maintains full 12 A per channel capability only when T_J ≤ 125 °C in typical notebook VRM layouts. The AO4724 datasheet specifies absolute maximum ratings and thermal curves referenced to this limit.

Does the AO4724 support 3.3 V gate drive?

The AO4724 is not fully characterized for reliable operation with 3.3 V gate drive. Its gate threshold voltage V_GS(th) is specified from 1.2 V to 2.5 V, but R_DS(on) rises sharply below 4.5 V V_GS; at 3.3 V, R_DS(on) exceeds 60 mΩ, doubling conduction loss. The AO4724 is designed for 5 V–10 V gate drive, and its 12 A rating assumes V_GS ≥ 4.5 V. For 3.3 V logic interfaces, external level-shifting or gate boosting is required.

Is the AO4724 halogen-free and RoHS compliant?

Yes, the AO4724 is halogen-free and RoHS compliant per AOS Green Policy. It meets Br/Cl <900 ppm and total halogens ≤1500 ppm at homogeneous material level. No "L" suffix is used because the AO4724 was introduced after 2010 and ships exclusively in green packaging. All AO4724 units distributed by Aetrix Electronics carry full halogen-free certification documentation aligned with IEC 61249-2-21.

How is the thermal pad (pin 8) of the AO4724 connected internally?

The thermal pad (pin 8) of the AO4724 is electrically connected to the drain of the low-side MOSFET (Q2). It is not internally tied to source or gate terminals. Proper PCB layout requires connecting pin 8 to a dedicated thermal copper pour tied to the low-side drain net - not to ground or source - to avoid short circuits. This connection also provides the primary thermal path; insufficient solder coverage degrades R_θJA by >30%. The AO4724 thermal pad design is documented in AOS Application Note AN-1001.

Can the AO4724 be used in parallel with another AO4724 for higher current?

Parallel operation of two AO4724 devices is not recommended due to mismatch in dynamic parameters (e.g., t_on/t_off, Q_g) that cause unequal current sharing during switching transitions. While static R_DS(on) matching is ≤5%, transient imbalance can exceed 40% peak current skew. For higher current, AOS recommends the AOZ5311DI - a 30 V, 30 A dual-phase controller with integrated drivers optimized for paralleled MOSFETs. The AO4724 is intended for single-chip dual-channel use, not multi-device stacking.