Alpha & Omega Semiconductor Inc. AONS36303

Overview

AONS36303 from Alpha & Omega Semiconductor is a 30V N-channel Trench Power MOSFET optimized for high-current, low-loss switching in DC/DC converters. It delivers 83A continuous drain current at V_GS=10V, <3.28mΩ R_DS(ON) at 10V, and <5.15mΩ at 4.5V, with 100% UIS and R_g tested - enabling robust operation in server point-of-load (POL) power stages.

For engineers reviewing the AONS36303 datasheet, pinout, applications, or equivalent options, key selection criteria include its DFN5x6 package thermal performance (R_θJC = 3.5°C/W), gate charge profile (Q_g(10V) = 19–32nC), avalanche energy rating (E_AS = 20–33mJ), and body diode recovery characteristics (Q_rr = 17nC, t_rr = 11ns).

Technical Context

The AONS36303 employs Trench Power MOSFET technology to achieve ultra-low on-resistance and fast switching dynamics. Its gate threshold voltage (1.4–2.2V typ) supports 4.5V logic-level drive, while low Q_gd/Q_g ratio (3.6nC/19–32nC) improves hard-switching efficiency and reduces Miller-induced turn-on risk.

Thermally, it features a copper-clip DFN5x6 package with exposed drain pad for direct heatsinking. The R_θJA of 55°C/W (1in² FR-4, 2oz Cu) and R_θJC of 3.5°C/W enable high-power density designs, and its 100% unclamped inductive switching (UIS) testing confirms ruggedness under transient overloads in synchronous buck topologies.

Key Specifications

Pinout & Package

Package: DFN5x6 (5mm × 6mm, 1.0mm height), thermally enhanced with exposed drain pad on bottom side. Pin 1 marked by notch or dot; leads are surface-mount only.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IPP036N04L and SiR626DP, the AONS36303 offers superior thermal resistance (R_θJC = 3.5°C/W) and lower gate charge (Q_g = 19–32nC), making it optimal for space-constrained, high-frequency POL designs where junction temperature control and driver efficiency are critical.

Availability

AONS36303 is available at Aetrix Electronics and suitable for server point-of-load (POL) converters, GPU VRM power stages, and industrial DC/DC supplies requiring stable component supply, high-current capability, and rugged avalanche performance.

Supply support for AONS36303 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 ICs for computing, consumer, and industrial markets.

The AONS36303 belongs to AOS's Trench Power MOSFET product line, engineered specifically for high-current, high-frequency DC/DC conversion in datacenter and telecom infrastructure where low R_DS(ON), fast switching, and thermal reliability are mandatory.

FAQ

What is the maximum continuous drain current rating for the AONS36303 at 100°C case temperature?

The AONS36303 supports 36A continuous drain current at T_C = 100°C, as specified in its Absolute Maximum Ratings table. This derated value reflects thermal limits under real-world heatsinking conditions and must be used - not the 83A rating at T_C = 25°C - when designing for sustained high-power operation. The AONS36303 datasheet provides de-rating curves confirming this linear reduction down to zero current at 150°C junction temperature.

Does the AONS36303 support 4.5V gate drive in practical applications?

Yes, the AONS36303 is fully characterized at V_GS = 4.5V, with R_DS(ON) guaranteed at <5.15mΩ and gate threshold voltage (V_GS(th)) specified from 1.4V to 2.2V. This ensures robust enhancement with standard 5V logic outputs or microcontroller GPIOs, and its low Q_g(4.5V) = 10–16nC enables efficient drive without external buffers. The AONS36303 transfer characteristics curve (Figure 2) confirms strong transconductance at 4.5V across temperature.

How is avalanche ruggedness verified for the AONS36303?

The AONS36303 undergoes 100% unclamped inductive switching (UIS) testing per JEDEC JESD24-1, with each unit validated to deliver minimum E_AS = 20mJ at T_J = 25°C and 33mJ at T_J = 125°C. Test conditions use L = 0.01mH, I_AS = 52A, and V_DS spike ≤ 36V. This 100% screening - documented in the AONS36303 datasheet's Product Summary - ensures field reliability in synchronous buck freewheeling and inductive load switching without external protection.

What is the thermal resistance from junction to case (R_θJC) for the AONS36303, and how is it measured?

The AONS36303 has a maximum R_θJC of 3.5°C/W, measured with the device mounted to a large heatsink under steady-state conditions per JEDEC 51-14. This value reflects the intrinsic thermal path from silicon junction to the exposed drain pad surface and is independent of PCB layout. It enables accurate junction temperature prediction (T_J = T_C + P_D × R_θJC) when the DFN5x6 drain pad is soldered to a thermal plane or heatsink - a key advantage over leaded packages. The AONS36303 datasheet specifies this in its Thermal Characteristics table.

Can the AONS36303 be used in parallel configurations, and what design considerations apply?

Yes, the AONS36303 is suitable for paralleling due to its positive temperature coefficient of R_DS(ON) (confirmed in Figure 4) and matched gate threshold voltage (1.4–2.2V). Key design practices include symmetrical PCB layout, individual gate resistors (≥1Ω), and Kelvin-source routing to minimize current imbalance. Its dual-source pins (Pins 5 & 6) and five-drain terminals reduce parasitic inductance, improving dynamic current sharing. The AONS36303 datasheet recommends verifying thermal coupling and using gate drive waveforms with tight skew (<2ns) for optimal performance.