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).

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Self-Capacitance Waterproof button solution

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Title language Type Format File Size Date
Self-Capacitance Waterproof Demo Design Data PCB Design Files ZIP 1.38 MB
RL78/G23 Self-capacitance Waterproof Touch Button Demo Sample Software Rev.1.00 - Sample Code
Related Files: Application Note
日本語 Sample Code ZIP 6.52 MB
RA2L1 Group Self-capacitance Waterproof Touch Button Demo Sample Software - Sample Code
Related Files: Application Note
日本語 Sample Code ZIP 3.16 MB