Alpha & Omega Semiconductor Inc. AOZ1321DI-06

Overview

AOZ1321DI-06 from Alpha & Omega Semiconductor is a single-channel high-side power-distribution switch featuring a 70 mΩ N-channel MOSFET, 1.5 A continuous current rating, 2.7 V to 5.5 V input voltage range, active-high enable logic, and integrated thermal shutdown - deployed in USB power management for notebook computers.

For engineers reviewing the AOZ1321DI-06 datasheet, pinout, applications, or equivalent options, this device is selected for robust short-circuit protection, reverse-current blocking, open-drain fault flag with deglitching, and low-voltage operation down to 2.7 V in space-constrained USB load-switch designs.

Technical Context

The AOZ1321DI-06 implements a charge-pump–driven high-side N-channel MOSFET switch, enabling full gate overdrive without external components and supporting operation from 2.7 V. Its proprietary rise/fall time control minimizes inrush current during hot-plug events with capacitive loads up to 470 μF.

It integrates undervoltage lockout (2.5 V threshold with 200 mV hysteresis), overcurrent detection (trip threshold 1.6–2.7 A), and thermal shutdown (135 °C trip, 105 °C recovery). The open-drain OC pin provides fault indication with 4–15 ms deglitch timing.

Key Specifications

Pinout & Package

AOZ1321DI-06 is packaged in an eMSOP-8 (EPAD) thermally enhanced leaded package with exposed thermal pad, optimized for PCB heat dissipation in compact USB ports.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side USB load-switch applications.

Compared with AOZ1321DI-06, TUSB2036IRHBR embeds USB PHY functionality but sacrifices independent fault control, while TPS2051BDBVR offers lower R_DS(ON) but requires additional components to match AOZ1321DI-06's integrated protection and reverse-blocking capability.

Availability

AOZ1321DI-06 is available at Aetrix Electronics and suitable for notebook computer USB power management, industrial USB I/O modules, and USB 3.0 bus-powered hubs requiring stable component supply, long-term lifecycle support, and RoHS-compliant green packaging.

Supply support for AOZ1321DI-06 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, power ICs, and load switches for computing, consumer, and industrial markets.

The AOZ13xx family was designed specifically for USB and general-purpose power-distribution switching - emphasizing robust short-circuit tolerance, low-voltage operability, and integrated protection in thermally efficient packages.

FAQ

What is the maximum continuous current rating of the AOZ1321DI-06?

The AOZ1321DI-06 is rated for 1.5 A maximum continuous current at ambient temperatures up to +85 °C. This rating assumes proper PCB thermal design using the exposed EPAD and adequate copper area. At higher junction temperatures or with insufficient heatsinking, derating applies per the Θ_JA = 60 °C/W specification for the eMSOP-8 package.

Does the AOZ1321DI-06 provide reverse current blocking, and how is it implemented?

Yes, the AOZ1321DI-06 provides reverse current blocking when disabled - meaning it prevents current flow from OUT to IN. This is achieved by the intrinsic body diode orientation of its high-side N-channel MOSFET combined with gate control that fully turns off the channel. No external diode is required, simplifying USB topology design and improving efficiency.

What is the purpose of the OC pin on the AOZ1321DI-06, and how should it be interfaced?

The OC (Overcurrent) pin on the AOZ1321DI-06 is an open-drain output that asserts low during overcurrent, thermal shutdown, or UVLO conditions. It must be pulled up externally (typically to 3.3 V or 5 V) and debounced in firmware. Its 4–15 ms deglitch window rejects transient spikes, ensuring reliable fault detection for the AOZ1321DI-06 in noisy USB environments.

Can the AOZ1321DI-06 operate from a 3.3 V supply, and what performance changes occur?

Yes, the AOZ1321DI-06 operates across 2.7 V to 5.5 V, including 3.3 V. At 3.3 V, R_DS(ON) increases slightly (to ~95 mΩ typical), and rise/fall times lengthen (e.g., tr ≈ 0.7 ms), but all protections - OC detection, thermal shutdown, and UVLO - remain fully functional. The internal charge pump ensures gate drive remains effective down to the minimum input voltage.

How does the AOZ1321DI-06 handle short-circuit faults, and what is the current-limit behavior?

Upon short-circuit detection, the AOZ1321DI-06 enters constant-current mode, limiting output current to 1.6–2.7 A (typical trip at 2.3 A). Simultaneously, it pulls the OC pin low and initiates thermal monitoring. If power dissipation causes die temperature to reach 135 °C, thermal shutdown activates - disabling the switch until temperature falls to 105 °C, then auto-restarting to assess fault persistence.