Alpha & Omega Semiconductor Inc. AONR62921

Overview

AONR62921 from Alpha & Omega Semiconductor is a 100V N-Channel MOSFET in DFN 3.3×3.3 EP package, featuring R_DS(ON) < 10.2 mΩ at V_GS = 10 V, 50 A continuous drain current, and logic-level gate drive compatibility. It serves as a high-efficiency synchronous rectifier in compact AC/DC power adapters and DC-DC converters.

For engineers reviewing the AONR62921 datasheet, pinout, applications, or equivalent options, key selection criteria include its 100V breakdown rating, low gate charge (Q_g = 35 nC at 10 V), avalanche-rated ruggedness, thermal resistance (R_θJC = 2.3 °C/W), and DFN package suitability for high-density PCB layouts.

Technical Context

The AONR62921 employs Trench Power AlphaSGT™ technology to achieve low R_DS(ON) and high current density in a thermally enhanced DFN package. Its gate threshold voltage (1.3–2.3 V) enables direct interfacing with 3.3 V and 5 V controllers without level-shifting.

It supports unclamped inductive switching (UIS) with 100% testing, features low output charge (Q_oss = 30 nC), and delivers fast switching performance: t_d(on) = 7.5 ns, t_f = 5 ns, and trr = 25 ns - critical for high-frequency synchronous rectification.

Key Specifications

Pinout & Package

Package: DFN 3.3 × 3.3 mm with exposed thermal pad (EP). Bottom-side thermal pad enhances heat transfer to PCB copper, critical for high-current operation without discrete heatsinks.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BSC014N06LS6 and SiR626DP, the AONR62921 uniquely balances 100 V rating, 50 A capability, sub-10.2 mΩ R_DS(ON), and logic-level drive - making it optimal for space-constrained, high-voltage synchronous rectification where both voltage margin and gate simplicity matter.

Availability

AONR62921 is available at Aetrix Electronics and suitable for USB-PD adapters, telecom rectifiers, automotive auxiliary supplies, and high-density DC-DC converters requiring stable component supply and consistent DFN 3.3×3.3 packaging.

Supply support for AONR62921 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 modules for computing, consumer, industrial, and automotive markets.

The AONR62921 belongs to AOS's AlphaSGT™ trench MOSFET product line, engineered specifically for high-efficiency, high-frequency synchronous rectification and DC-DC conversion in thermally constrained, high-power-density applications.

FAQ

What is the maximum continuous drain current rating for the AONR62921?

The AONR62921 supports 50 A continuous drain current at T_C = 25 °C, derating to 37 A at T_C = 70 °C and 13.5 A at T_C = 100 °C. This rating is package-limited and validated under JEDEC-standard test conditions using a 1 in² FR-4 board with 2 oz copper. The AONR62921 datasheet specifies these values in its Absolute Maximum Ratings table.

Does the AONR62921 require a gate driver, or can it be driven directly by a microcontroller?

The AONR62921 can be driven directly by 3.3 V or 5 V microcontrollers due to its logic-level gate threshold (V_GS(th) = 1.3–2.3 V) and guaranteed enhancement at V_GS ≥ 4.5 V. However, for high-frequency switching (>200 kHz) or high-current applications, a dedicated gate driver is recommended to manage its 35 nC total gate charge and minimize switching losses. The AONR62921's low R_g (0.6–1.8 Ω) further supports clean edge control without external damping.

Is the AONR62921 suitable for avalanche energy handling in unclamped inductive switching?

Yes, the AONR62921 is 100% tested for unclamped inductive switching (UIS) and rated for E_AS = 68 mJ at L = 0.1 mH. This ruggedness is confirmed in the datasheet's Absolute Maximum Ratings and Electrical Characteristics sections. The AONR62921's trench AlphaSGT™ structure contributes to uniform avalanche distribution, making it suitable for flyback, forward, and LLC resonant converters where inductive energy recovery occurs.

What is the thermal resistance from junction to case (R_θJC) for the AONR62921, and how does it impact heatsinking?

The AONR62921 has R_θJC = 2.3 °C/W, measured with the device mounted to a large heatsink. This low value indicates highly efficient heat transfer from the silicon die to the package's exposed thermal pad. In practice, this allows the AONR62921 to dissipate over 21 W continuously when the case temperature is held at 25 °C - enabling compact, heatsinkless designs when paired with adequate PCB copper area. The AONR62921's DFN 3.3×3.3 EP package is optimized for such thermal conduction paths.

Can the AONR62921 be used as a replacement for Schottky diodes in synchronous rectification?

Yes, the AONR62921 is explicitly designed for synchronous rectification in AC/DC adapters and DC-DC converters, replacing Schottky diodes to reduce forward voltage drop and conduction loss. Its low R_DS(ON) (<10.2 mΩ) yields significantly lower power loss than typical 40 V Schottkys (V_F ≈ 0.5 V), especially at currents above 10 A. The AONR62921's body diode characteristics (V_SD = 0.7–1.0 V, Q_rr = 123 nC) are also optimized for fast recovery in high-frequency rectification circuits.