WATERPROOF-SELF-CT-REF

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.

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). The table below details the type of technologies that can be used and their related issues. These issues are resolved with Renesas' solution. The active shield makes the self-capacitance buttons water resistant for easy design. Additionally, the self-capacitance buttons and active shielding is enable using one chip without any additional parts.