Proximity switch reference design using CapTIvate teaching button

This reference design demonstrates how to implement a capacitive touch button, commonly used as a setting button in a proximity switch, in an ultra-small 3.5mm wide PCB based on TI's CapTIvate™ technology. When combined with the highly integrated IO-Link PHY, flexible PNP or NPN outputs are possible. The SIO stage provides reverse polarity, ESD, EFT and surge protection, making the design compliant with IEC 61000-4 standards. Hall sensors with analog output signals enable flexible use by teaching the distance to magnetic objects via a capacitive teach button. This analog signal is captured by the MCU's integrated ADC.

characteristic

• ● Capacitive teaching button using CapTIvate technology:
  • ● Support metal touch and waterproof design
  • ● Self-capacitance and mutual capacitance electrodes
  • ● Improves immunity against power line, radio frequency and other environmental noise
• ● Highly integrated output driver:
  • ● NPN, PNP, IO-Link (optional)
  • ● 3.3V or 5.0V LDO; 20mA
  • ●Reverse polarity protection
  • ● ESD, EFT and surge protection compliant with IEC 61000-4 standard
  • ● 50 to 350mA configurable output current limit
• ● 3.5mm wide PCB