Alpha & Omega Semiconductor Inc. AOZ13937DI-04

Overview

AOZ13937DI-04 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 8 A continuous current, 20 mΩ typical R_ON, 3.4–32 V input range, and true reverse-current blocking (IDTRCB) with 35 mV regulation, enabling robust multi-port PD applications in notebooks and docking stations.

For engineers reviewing the AOZ13937DI-04 datasheet, pinout, applications, or equivalent options, this page provides verified technical context, validated pin functions, confirmed thermal shutdown and OVP latch-off behavior, and real-world design meaning for soft-start, IDTRCB, and surge current handling in Type-C EPR systems.

Technical Context

The AOZ13937DI-04 integrates back-to-back MOSFETs to enable bidirectional isolation and true reverse-current blocking, with VIN–VOUT regulated at 35 mV under light load. Its programmable POVP pin sets OVP thresholds at either 23 V or 33 V, and FLTB provides open-drain fault signaling for both over-voltage and thermal shutdown events.

Unlike the auto-restart AOZ13937DI-03, the AOZ13937DI-04 implements latch-off recovery: after four failed startup retries under short-circuit conditions or upon thermal/over-voltage fault detection, it remains latched off until ENB is toggled or VIN is cycled - eliminating uncontrolled re-attempts in safety-critical power paths.

Key Specifications

Pinout & Package

AOZ13937DI-04 is housed in a thermally enhanced DFN3x3-12L package (3 mm × 3 mm, 12-pin) with exposed thermal pad (EXP) for low R_th(J-C) = 2.5 °C/W. The package operates from –40 °C to +125 °C junction temperature and supports RoHS-compliant reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AOZ13937DI-03 and TPS25982L, the AOZ13937DI-04 uniquely combines latch-off fault containment, 35 mV IDTRCB regulation, and 20 A surge capability in a 3×3 mm footprint - making it the only option that satisfies USB PD 3.1 EPR safety, reverse-blocking, and transient robustness requirements simultaneously.

Availability

AOZ13937DI-04 is available at Aetrix Electronics and suitable for USB Type-C PD power switches, notebook computers, docking stations, and power ORing applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for AOZ13937DI-04 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, thermally robust protection switches for USB Type-C PD and high-current ORing applications - engineered to replace discrete FETs and diodes while meeting IEC 61000-4-2/4-5 and JEDEC reliability standards.

FAQ

What is the key functional difference between AOZ13937DI-04 and AOZ13937DI-03?

The AOZ13937DI-04 implements latch-off fault recovery, whereas AOZ13937DI-03 uses auto-restart. Specifically, AOZ13937DI-04 shuts down permanently after four failed startup retries under short-circuit conditions or after thermal/OVP faults, requiring an ENB toggle or VIN cycle to resume. This behavior is explicitly defined in the datasheet's Table 3 and ensures deterministic fault containment - a critical distinction for AOZ13937DI-04 in safety-sensitive USB PD implementations.

How does the Ideal Diode True Reverse Current Blocking (IDTRCB) function in AOZ13937DI-04?

The IDTRCB feature in AOZ13937DI-04 actively regulates the voltage difference between VIN and VOUT to 35 mV under light/no-load conditions, preventing any reverse current flow from VOUT to VIN. If VOUT rises above VIN −35 mV, the internal gate driver forces the back-to-back MOSFETs off. This behavior is confirmed in the datasheet's Detailed Description (Page 10) and Typical Characteristics (Page 7), and is independent of ENB state - ensuring blocking even during fault or shutdown.

What is the maximum recommended output capacitance for AOZ13937DI-04 with an 8 A load?

Per Figure 6 on Page 12 of the datasheet, the maximum recommended output capacitance (COUT) for AOZ13937DI-04 with an 8 A resistive load is approximately 700 µF when using the minimum recommended soft-start capacitor (Css_min). Exceeding this value without increasing Css risks violating the MOSFET's Safe Operating Area during startup due to prolonged current-limit conduction - a condition that triggers latch-off in AOZ13937DI-04 after four retries.

Does AOZ13937DI-04 support programmable over-voltage protection, and how is it configured?

Yes, AOZ13937DI-04 supports programmable over-voltage protection via the POVP pin. Applying a DC voltage <1.25 V sets the OVP threshold to 33 V (min), while >1.4 V sets it to 23 V (min). Alternatively, a resistor divider from POVP to GND achieves the same thresholds. The setting is latched at startup and remains fixed during operation - a behavior explicitly documented in Table 1 and the Over-Voltage Protection section (Page 10) of the AOZ13937DI-04 datasheet.

What thermal performance metrics are specified for AOZ13937DI-04, and how do they impact PCB layout?

AOZ13937DI-04 specifies R_th(J-C) = 2.5 °C/W (junction-to-case bottom) and R_th(J-A) = 36 °C/W (junction-to-ambient). The low R_th(J-C) means effective heat transfer depends critically on soldering the exposed thermal pad (EXP) to large copper areas across multiple PCB layers via ≥6 thermal vias - as emphasized in the Pin Description (Page 2) and Thermal Characteristics (Page 4). Neglecting this degrades thermal margin and risks premature thermal shutdown at 8 A continuous load.