Alpha & Omega Semiconductor Inc. AOI1R4A70

Overview

AOI1R4A70 from Alpha & Omega Semiconductor is a 700 V, 15 A N-channel power MOSFET in TO-251A (IPAK) package, featuring 1.4 Ω max R_DS(ON), 7.4 nC typical gate charge, and 100% UIS-tested ruggedness. It serves as a primary switching device in offline flyback SMPS, AC-DC adapters, and LED lighting drivers operating up to 150 °C junction temperature.

For engineers reviewing the AOI1R4A70 datasheet, pinout, applications, or equivalent options, key selection criteria include its 700 V BVDSS rating, 1.4 Ω RDS(ON) at VGS = 10 V, TO-251A thermal performance (RθJC = 2.6 °C/W), body diode reverse recovery time (trr = 176 ns), and avalanche energy rating (EAS = 1 mJ).

Technical Context

The AOI1R4A70 employs Alpha & Omega's proprietary aMOS5™ technology to achieve low conduction loss and optimized switching behavior. Its 1.4 Ω R_DS(ON) and 7.4 nC Q_g enable high-efficiency operation in 65–100 kHz flyback converters while maintaining EMI control via reduced dv/dt sensitivity (100 V/ns ruggedness).

It integrates an enhanced body diode with 176 ns reverse recovery time and 1.4 mC Q_rr, supporting robust unclamped inductive switching (UIS) and fast recovery in discontinuous conduction mode (DCM) topologies. Thermal design is enabled by R_θJC = 2.6 °C/W and R_θJA = 45 °C/W (FR-4, 2 oz Cu).

Key Specifications

Pinout & Package

AOI1R4A70 is housed in a TO-251A (IPAK) surface-mount package with gull-wing leads, designed for high-power density PCB layouts and improved thermal transfer via exposed drain pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP7NK70ZFP and IPP65R190C7, the AOI1R4A70 uniquely combines 700 V rating, 15 A current capability, 100% UIS validation, and TO-251A surface-mount compatibility-making it the sole option for space-constrained, high-surge industrial flyback designs requiring guaranteed avalanche robustness.

Availability

AOI1R4A70 is available at Aetrix Electronics and suitable for flyback SMPS, USB-C PD adapters, and commercial LED lighting systems requiring stable component supply, long-lifecycle support, and traceable sourcing for production ramp-up.

Supply support for AOI1R4A70 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 AOI1R4A70 belongs to AOS's aMOS5™ 700 V power MOSFET family, engineered specifically for high-efficiency, high-reliability offline AC-DC conversion in space- and thermal-constrained applications.

FAQ

What is the maximum continuous drain current rating for AOI1R4A70 at TC = 100°C?

The AOI1R4A70 supports 15 A continuous drain current at case temperature TC = 25°C, derating linearly to approximately 7.5 A at TC = 100°C per the current de-rating curve (Figure 10). This reflects its RθJC = 2.6 °C/W and TJ,max = 150°C thermal limit. The AOI1R4A70 must be mounted on adequate copper area or heatsink to sustain this current in real-world conditions.

Does AOI1R4A70 have a fully characterized body diode for synchronous rectification?

No-the AOI1R4A70 features an enhanced body diode optimized for robustness and fast reverse recovery (trr = 176 ns, Qrr = 1.4 mC), but it is not rated or characterized for synchronous rectification duty. Its body diode is intended for freewheeling and clamping in flyback and other hard-switched topologies, not for active-controlled conduction. For synchronous rectification, discrete Schottky or dedicated SR controllers paired with low-VF diodes are recommended instead of relying on the AOI1R4A70 body diode.

Is AOI1R4A70 pin-compatible with AOD1R4A70?

No-AOI1R4A70 uses the TO-251A (IPAK) package with gull-wing leads, while AOD1R4A70 uses TO-252 (DPAK) with鸥翼 leads. Though both share identical electrical specifications and die, their land patterns, thermal pad layout, and soldering profiles differ. PCB redesign is required to substitute AOI1R4A70 for AOD1R4A70 or vice versa; they are functionally equivalent but not mechanically interchangeable.

What gate resistor value is recommended for AOI1R4A70 in a 65 kHz flyback design?

A gate resistor of 5–10 Ω is recommended for AOI1R4A70 in 65 kHz flyback applications to balance switching speed and EMI. With 7.4 nC Qg and typical driver output impedance, 5 Ω yields ~37 ns rise/fall times-sufficient to minimize overlap loss while containing dv/dt-induced noise. Values below 3 Ω risk excessive ringing; above 15 Ω increase switching loss unnecessarily. The AOI1R4A70's 100% Rg tested specification (7.3 Ω typ) ensures consistency across lots when selecting external RG.

How is the 1 mJ EAS rating for AOI1R4A70 validated?

AOI1R4A70's 1 mJ EAS (Effective Avalanche Energy) rating is validated per JEDEC JESD24-11 using unclamped inductive switching (UIS) tests at L = 60 mH, IAS = 0.3 A, RG = 25 Ω, and starting TJ = 25°C. Each unit undergoes 100% production UIS screening-ensuring every AOI1R4A70 shipped meets minimum 1 mJ single-pulse avalanche capability without degradation. This testing directly supports reliability in surge-prone AC-DC front ends.