Reference Designs Ease USB PD/USB-C Battery Charging Applications

Renesas Electronics introduces two reference designs that promise to simplify and speed the development of USB Power Delivery (PD3.0) and USB-C™ battery charging applications such as USB-C computing hubs, power banks, car chargers, SSD enclosures, point of sale (POS) printers, and desktop displays. The RTK-251-1PowerBank3 and RTK-251-BuckBoostConverter2 are USB-IF PD3.0 certified design kits and represent the first in a new series of reference designs for applications implementing the USB Type-C™ power and data connection standard.


The RTK-251-1PowerBank3 board is a 3-cell (series connected) Li-ion battery power bank reference design that employs the R9A02G011 USB PD3.0 controller and ISL95538B buck-boost Narrow Voltage Direct Charging (NVDC) battery charger. Ideal for USB-C multi-battery-cell power banks, the reference design board includes one USB Type-C port that supports the Dual Role Power (DRP) feature, delivering power in both directions via power source and power sink modes. When the power bank is in sink mode, it requests 5V, 9V, 15V, or 20V from a USB PD3.0 provider such as an AC adapter. When the power bank is in source mode, the Li-ion battery supplies 5V up to 20V requested from a PC, tablet, or smartphone. In addition, the RTK-251-1PowerBank3 changes its DRP role based on the remaining battery capacity displayed on the board’s LEDs.

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The RTK-251-BuckBoostConverter2 is a DC/DC module that employs the R9A02G011 USB PD3.0 controller and the ISL95338 bidirectional buck-boost voltage regulator. The RTK-251-BuckBoostConverter2 reference design board is ideal for USB-C hubs as part of the USB-PD AC adapter connection. It accepts 19V with 4.73A DC input power and produces USB-PD3.0-compatible VBUS output power. The reference design board supports Programmable Power Supply (PPS) and has two USB Type-C receptacles for VBUS power output.


RTK-251-1PowerBank3 features include:

  • 1 port USB-PD power bank reference design board includes:
  • R9A02G011 power delivery controller supports dual role operation
  • ISL95538B buck-boost battery charger up to 4-cells (default 3-cell setting)
  • Type-C port supporting PD3.0 with PPS x1 and DRP with bypass mode
  • Supports OVP, OCP, OTP and UVLO protections
  • Supports USB-C authentication
  • SDK sample code and parameter settings configured through Renesas USB Power Delivery Controller Flash ROM Image Generator software tool

RTK-251-BuckBoostConverter2 features include:

  • 2-port DC/DC Module reference design board includes:
  • Two R9A02G011 power delivery controllers
  • Two ISL95338 buck-boost voltage regulators
  • DC/DC: For 3V, 5V, and PD out = ISL95338 x2
  • Type-C port supporting PD3.0 x2
  • 12V~19V for DC IN
  • Supports PD output voltage
  • Fixed = 5V, 9V, 15V, 20V, and additional user setting 3 PDOs
  • PPS = 20V Programmable (3.3V to 21V)
  • Supports USB-C authentication
  • SDK sample code and parameter settings configured through Renesas USB Power Delivery Controller Flash ROM Image Generator software tool

The RTK-251-1PowerBank3 Reference Design Kit is available now priced at $119 and the RTK-251-BuckBoostConverter2 Reference Design Kit costs $127. To jumpstart USB-PD and USB-C designs, download both reference designs kits.

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