New Industry Products

Alpha and Omega Semiconductor Debuts Ideal Diode Reverse Current Protection Switch

September 09, 2021 by Gary Elinoff

Alpha and Omega Semiconductor’s (AOS) smart protection switch is aimed at Type-C Power Delivery applications.

The AOZ13984DI-02 and AOZ13987DI-02 employ back-to-back trench MOSFETs to effect an ideal diode true reverse current blocking (IDTRCB) solution, allowing for no reverse current under any conditions. Thanks to AOS’s co-packaging technology, the company was able to combine its control functions along with the MOSFETs to attain a complete solution, operating over a range of from 3.4V to 22V, with a 28V absolute maximum.

Simplified block diagram of the AOZ13984DI-02 and AOZ13987DI-02. Image courtesy of the AOZ13987DI-02 datasheet


In addition to blocking any reverse current, the new device has very low “ON” resistances; 20mΩ for AOZ13987DI-02 and 33mΩ for AOZ13984DI-02. Thus little power is wasted, and less destructive, parasitic heat is generated.

As noted by Peter Cheng, Power IC Senior Marketing Director at AOS. “The thinner profile, higher power, and greater flexibility offered by USB Type-C and USB PD 3.0 standards have allowed many notebook computers to only use Type-C ports for both power delivery and as a high-speed interface. Thus, eliminating the need for a dedicated power connector. As multiple Type C ports have become ubiquitous in consumer and computing designs, AOS’s new family of ideal diode-based protection switches offer a robust, reliable solution. And as always, AOS’s ability to combine TrenchFET technology with leading IC design enables a compact, efficient solution.”


Features Common to both the AOZ13987DI-02 and the AOZ13984DI-02

Both smart protection switches feature ideal diode true reverse current blocking (IDTRCB) and offer programmable soft-start.

Both smart protection switches are applicable to dual port applications. Image courtesy of AOZ13984DI-02 datasheet


The devices also offer VIN Under-Voltage Lockout (UVLO) and VIN Over-Voltage Lockout (OVLO). There is also thermal shutdown protection. A dedicated pin flags both the overvoltage and thermal faults.

Both smart protection switches feature internal soft-start circuit controls. This will serve to limit the high inrush currents concurrent with highly capacitive loads, and the slew rate can be adjusted using an external capacitor.

The units feat a high safe operating area (SOA) to handle the high current and the wide ranging variations of output capacitances to be encountered on VOUT.


Important Electrical Specifications


  AOZ13984DI-02 AOZ13987DI-02
Continuous Sink Current 5.5A 8A
Peak current for 10ms @ 2% duty cycle 15A 20A
Thermal resistance, junction to case 2.8°C/W 2°C/W
Thermal resistance junction to ambient 36°C/W 35°C/W


  • Input quiescent current is the same for both devices: 550μA typical, 750μA maximum
  • Input shutdown current is also the same for both units: 32μA typical and 48μA maximum
  • Input Over-voltage Protection for both devices is 24V



  • Thunderbolt/USB Type-C PD power switch
  • Power Oring
  • Docking station
  • Dongles
  • Notebook computers


Physical Considerations

  • The AOZ13984DI-02 and the AOZ13987DI-02 are both available in thermally enhanced 3 x 3mm DFN-12 packages
  • The devices operate over -40 to +125°C junction temperature ranges


Regulatory and Safety

  • IEC 61000-4-2 (electrostatic discharge) to 8kV on VIN and VOUT
  • IEC 61000-4-5 (surge testing) to 35 V on VIN
  • ESD rating, human body model is ±4kV



  • Both units are RoHS compliant


Featured image used courtesy of Alpha and Omega Semiconductor.