Alpha & Omega Semiconductor Inc. AOZ13937DI-02

Overview

AOZ13937DI-02 from Alpha and Omega Semiconductor is a high-side smart protection switch with latch-off fault recovery, designed for USB Type-C PD power path control. It delivers 7 A continuous current, 20 mΩ typical R_ON, 3.4–32 V input range, and integrated Ideal Diode True Reverse Current Blocking (IDTRCB) to prevent backfeed in multi-port systems.

For engineers reviewing the AOZ13937DI-02 datasheet, pinout, applications, or equivalent options, this device is selected for robust over-voltage, reverse-current, and thermal protection in high-reliability notebook, docking station, and Thunderbolt power ORing designs where fault latching ensures system-level safety compliance.

Technical Context

The AOZ13937DI-02 implements dual back-to-back MOSFETs with programmable soft-start via external CSS capacitor and configurable over-voltage lockout using POVP pin voltage selection (23 V or 33 V threshold). Its IDTRCB regulation maintains VIN–VOUT ≤ 35 mV under light load and transitions to low-R_ON conduction at full load.

Fault response is strictly latch-off: thermal shutdown (140 °C), over-voltage, or startup short-circuit triggers permanent disable until EN toggle or VIN cycle. FLTB pin provides open-drain fault signaling for all three conditions, with no auto-restart behavior-distinguishing it from the AOZ13937DI-01 variant.

Key Specifications

Pinout & Package

AOZ13937DI-02 is housed in a thermally enhanced DFN3x3-12L package (3 mm × 3 mm, 0.9 mm height) with exposed thermal pad (EXP) for bottom-side heat dissipation. Junction temperature range is –40 °C to +125 °C; R_th(J–C) = 2.5 °C/W (bottom).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AOZ13937DI-01, AOZ13937DI-02 provides deterministic fault containment via latch-off behavior-critical for USB PD host systems requiring controlled power sequencing. Against TCK127G, AOZ13937DI-02 delivers 40% lower conduction loss and 40% higher surge capability, making it optimal for high-efficiency, high-reliability power path management.

Availability

AOZ13937DI-02 is available at Aetrix Electronics and suitable for USB Type-C PD power switches, notebook computers, and docking stations requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AOZ13937DI-02 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 and Omega Semiconductor (AOS) is a fabless power semiconductor company specializing in high-efficiency MOSFETs, power ICs, and advanced packaging for power conversion and protection.

The AOZ13937DI product line delivers smart high-side switches optimized for USB Power Delivery architectures, combining ultra-low R_ON, integrated protection, and compact thermally enhanced packages for space-constrained portable electronics.

FAQ

What is the key functional difference between AOZ13937DI-02 and AOZ13937DI-01?

The AOZ13937DI-02 implements latch-off fault recovery: after over-voltage, thermal shutdown, or startup short-circuit, it remains disabled until EN is toggled or VIN is cycled. In contrast, AOZ13937DI-01 auto-restarts after fixed intervals. This makes AOZ13937DI-02 appropriate for safety-critical USB PD host applications where uncontrolled re-enabling is unacceptable. Both share identical electrical specs including 20 mΩ R_ON and 7 A continuous rating.

How does the Ideal Diode True Reverse Current Blocking (IDTRCB) feature operate in AOZ13937DI-02?

The IDTRCB feature in AOZ13937DI-02 actively regulates the voltage drop between VIN and VOUT to ≤35 mV under light-to-moderate loads by adjusting gate drive to the back-to-back MOSFETs. If VOUT rises above VIN−35 mV-indicating potential reverse current-the switch turns off completely. This eliminates external diodes in ORing paths while maintaining tight forward conduction control, and is fully active during both steady-state and transient conditions in AOZ13937DI-02.

What is the recommended soft-start capacitor value for AOZ13937DI-02 in a 7 A, 100 µF C_OUT application?

For AOZ13937DI-02 driving a 100 µF output capacitor with 7 A resistive load, the recommended soft-start capacitor (CSS) is 5.6 nF, yielding a typical 1.8 ms 10–90% VOUT ramp time. This value balances inrush current limiting against MOSFET SOA stress during startup. Using less than the minimum CSS (e.g., <3.3 nF) risks triggering startup short-circuit protection due to excessive current limit duration; exceeding maximum CSS (e.g., >10 nF) extends ramp time excessively, increasing energy dissipation in linear mode.

Can AOZ13937DI-02 be used in 28 V USB PD 3.1 EPR applications?

Yes, AOZ13937DI-02 supports 28 V USB PD 3.1 Extended Power Range applications: its 3.4–32 V input range fully covers 28 V nominal operation, and its 39 V absolute maximum rating provides 11 V margin against transients. The 20 mΩ R_ON ensures <4 W conduction loss at 14 A peak (2×7 A), and its IEC 61000-4-5 45 V surge rating meets USB PD EPR system-level surge requirements without additional TVS devices.

How is thermal performance managed in the DFN3x3-12L package of AOZ13937DI-02?

AOZ13937DI-02 uses a DFN3x3-12L package with an exposed thermal pad (EXP) that serves as the common drain node and primary heat path. For optimal thermal performance, EXP must be soldered to a large copper area on the PCB bottom layer, connected via ≥6 thermal vias to internal ground or thermal planes. With this layout, R_th(J–C) is 2.5 °C/W (bottom), enabling 7 A continuous operation at +85 °C ambient. The top-side R_th(J–C) is 4.5 °C/W, so top-side heatsinking offers limited benefit.