Reduced BOM Cost 27W Rapid Charge™ AC/DC Digital Controller

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Supports USB Power Delivery 3.0, Qualcomm® Quick Charge 3.0 and 2.0, and Direct Charge Adapters; Companion to the iW657P USB PD 3.0 Controller

The iW1791 is a 27W output, high performance AC/DC RapidCharge power supply controller that supports USB Power Delivery (USB PD 3.0) and other rapid charging protocols. The device uses advanced source charging technology to integrate additional high voltage components and reduce the overall BOM cost in travel adapter applications.

It is optimized to work with Dialog’s iW657P USB PD interface controller in mobile device adapters to achieve fast and smooth voltage transition on request from the mobile device. The iW657P accepts fast charging protocols, including USB PD 3.0 and transmits all necessary information via an optocoupler to the iW1791, including voltage requests, output current limits, output voltage undershoot, output over-voltage, and fault and reset signals.

A full array of protection features includes Dialog’s SmartDefender+™ advanced hiccup technology to address soft short circuits in charger cables and connectors, helping to prevent excessive heat build-up and damage. Learn more about SmartDefender+ advanced hiccup technology here.

See the iW1781 for 45W USB PD 3.0 designs.

Qualcomm® Quick Charge™ is a product of Qualcomm Technologies, Inc.


  • Output power up to 27W
  • Optimized to Work with iW657P to Support Multiple RapidCharge Protocols:
    • Qualcomm® Quick Charge 4+
    • Direct Charge
  • Proprietary Secondary-To-Primary Digital Communication and Built-In Decoder: 
    • Reduces BOM and Significantly Simplifies Design
  • Single Optocoupler for All Rapid Charging Information
  • VCC Source Charging Technology – Reduces BOM and Keeps High Efficiency
    • Eliminates External Start-up Device



  • High Efficiency up to 90%
  • Low No-Load Power Consumption <20mW
  • Robust Protection Features
    • Output Over-Voltage Protection
    • Over-Current Protection
  • SmartDefender+™ Advanced Hiccup Technology 
    • Helps Protect Cables and Connectors from Excessive Heat and Damage by Reducing Average Power During Short Circuit by at Least 75%


  • USB PD 3.0, Qualcomm® Quick Charge™ 4+, Direct Charge, Other RapidCharge™ Protocols
  • USB PD 3.0 AC/DC Power Adapters for Smartphones, Tablets, Laptops and Other Mobile Devices 
  • USB PD 3.0 Power Supplies for Set Top Boxes, Displays, Speakers
  • USB PD 3.0 in-the-wall receptacles
  • Lamps and lighting fixtures with USB PD 3.0 ports

Block Diagrams

Typical Applications Diagram
Functional Block Diagram


Product Briefs and Summaries
Date Version
iW1791 Product Summary 05/05/2020 Rev. 1.6

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