The Renesas capacitive sensor, CTSU2 can utilize an active shield without any external components. Active shielding is effective in improving water resistance as well as improving the noise immunity of self-capacitance buttons.
The Self-Capacitance Waterproof Button Solution reference design compares the water resistance of traditional GND shields to the active shield for the self-capacitance buttons.

See the Waterproof Shower Controller for a sample application of a self-capacitance waterproof button solution.

Self-capacitance waterproof buttons - electrode board

  • This is based on a Renesas capacitive touch key solution with high sensitivity and high noise immunity
  • Usage example of the CTSU2's active shield
  • Self-capacitance touch buttons provide both water resistance and noise immunity
  • Supports the IEC 61000 4-3 Level 3 radiated electromagnetic noise immunity standard
  • This is applicable for various products such as white goods that require water resistance, water-related products and outdoor mounted equipment, etc.

Renesas' “Self-Capacitance Waterproof Button Solution” solves problems with conventional technology (GND shield, mutual capacitance buttons).

Self-Capacitance Waterproof button solution



Type Title Date
Application Note PDF 3.34 MB 日本語
Application Note PDF 4.52 MB 日本語
Application Note PDF 8.01 MB 日本語 , 简体中文
Application Note Log in to Download PDF 1.12 MB 日本語
Application Note PDF 1.33 MB 日本語
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Manual - Hardware PDF 2.28 MB 日本語
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PCB Design Files Log in to Download ZIP 1.38 MB
Application: Consumer Electronics, Industrial
Function: HMI
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Self-capacitance Waterproof Touch Button Solution

The capacitive touch sensing unit "CTSU2" has enhanced noise immunity functions and supports "active shields." It is also effective in improving the water resistance of self-capacitance touch buttons. In this demo, a GND shield and an active shield have been placed to compare the water resistance of each shielding method.