A touchless button solution can be widely used in homes (lighting switches, bathroom switches, etc.) and public locations (vending machines, electric door openers, etc.). A touch can be detected without directly touching the button; therefore, the adhesion of bacteria and dirt to the fingers is reduced. The touchless button solution lessens concerns over contaminated surfaces.

Renesas offers a reference design for the touchless button solution. To learn more, see the Touchless Button Reference Design page.

System Benefits​:

  • Entry-level RA 32-bit MCU with a Capacitive Touch Sensor Unit 2 (CTSU2) provides touchless control with high sensitivity and high noise immunity. All Renesas MCUs that contain a CTSU are also compatible.
  • Ultra-low Iq buck-boost can fully extract the power of a battery as low as 1.8V.
  • Output voltage can be adjusted by the I2C bus.



  • Elevators, vending machines, ticket selling machines
  • Toilet flushing, water faucets
  • Automatic door buttons
  • Kitchen appliances: Refrigerators, microwave ovens, range hoods, etc.