The iW9870 digital AC/DC controller integrates Renesas’ patented quasi-resonant (QR) valley mode switching technology with both CCM and DCM operation to enable light-weight, low-cost, and easily portable Zero Standby Power RapidCharge™ power supplies for smartphones, tablets, portable electronics products, monitors, TVs, and home appliances.

The iW9870 is optimized for driving GaN HEMTs directly to allow higher switching frequency and smaller magnetics at high efficiency.  The device supports USB Power Delivery 3.0 with PPS at output powers up to 63W when paired with Renesas’ iW760 secondary-side IC, which integrates fast charge protocol support, USB Type-C® control, and synchronous rectification FET control. The iW9870 also pairs with the iW765 for USB PD 3.1 applications to 100W. And pairs with the iW690 for fixed voltage, zero standby power supply applications to 140W.

Using proprietary intelligent power-saving technology, the iW9870 and one of the compatible secondary-side controllers enables Zero Standby Power fast charging power supplies that consume less than 5mW no-load standby power, ideal for adapters and chargers or any device that is left continuously connected to AC mains.

The iW9870 further reduces the total power supply BOM count and system cost by integrating innovative EMI reduction technologies, resulting in very low EMI power supplies using a minimum of external components. The iW9870’s adaptive QR mode also allows the use of smaller passive components, further reducing the overall BOM cost.

The iW9870 is compatible with Transphorm GaN technology.


  • Zero Standby Power
    • <5mW no-load power consumption (includes secondary-side IC power consumption)
  • Adaptive quasi-resonant (QR) control with DCM and CCM operation
    • Reduces overall transformer and passive component sizes
  • Adaptive, seamless multi-mode control (MMC) improves efficiency and eliminates audible noise
  • GaN compatible gate drive output with 5.9V max drive voltage
    • Compatible with direct HEMT gates or integrated GaN modules
  • Supports voltage sensing with dual polarity of VCC auxiliary winding for optimized EMI and transformer design
  • Small SOT23-6 package enables single-side PCB design when paired with the iW760, iW765, or iW690
  • AC unplug detection
  • Rich protection for:
    • Overvoltage (OVP)
    • Overcurrent (OCP)
    • User-configurable over-temperature
    • Shoot-through
    • Brown-in/brown-out
    • VSENSE/ISENSE short
    • Output short
    • Extra primary-side OCP and OVP if optocoupler fails
  • Zero Standby Power GaN Chipset Options
    • iW9870 + iW760: supports USB Power Delivery 3.0 with PPS power supplies to 63W
    • iW9870 + iW765: supports USB PD 3.1 power supplies to 100W
    • iW9870 + iW690: supports fixed voltage, power supplies to 140W
  • Compatible with Transphorm GaN devices
  • Hardwired state-machine solution prevents hacking of fast chargers. Learn more




  • Zero Standby Power, low-cost, light-weight 60W to 140W RapidCharge™ AC/DC power supplies and adapters for smartphones, tablets, in-wall power outlets, and other portable devices using USB PD
  • Zero Standby Power power supplies for TVs, monitors, home appliances


Type Title Date
Product Brief PDF 570 KB
Other Log in to Download ZIP 2.73 MB
Brochure PDF 5.49 MB 日本語
White Paper PDF 854 KB 日本語 , 简体中文
Datasheet Log in to Download PDF 1015 KB
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Design & Development

Software & Tools


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