Legacy Nxp Capacitive Touch Sensors

1. General description：

    The integrated circuit PCF8883 is a capacitive touch and proximity switch that uses a patented (EDISEN) digital method to detect a change in capacitance on a remote sensing plate. Changes in the static capacitance (as opposed to dynamic capacitance changes) are automatically compensated using continuous auto-calibration. Remote sensing plates (e.g. conductive foil) can be connected directly to the IC1 or remotely using a coaxial cable.

2. Features and benefits：

• Dynamic proximity switch

• Digital processing method

• Adjustable sensitivity, can be made very high

• Adjustable response time

• Wide input capacitance range (10 pF to 60 pF)

• Automatic calibration

• A large distance (several meters) between the sensing plate and the IC is possible

• Open-drain output (P-type MOSFET, external load between pin and ground)

• Designed for battery powered applications (I_DD = 3μA, typical)

• Output configurable as push-button, toggle, or pulse

• Wide voltage operating range (V_DD = 3 V to 9 V)

• Large temperature operating range (T_amb =-40℃ to +85℃)

• Internal voltage regulator

• Available in SOIC8 and wafer level chip-size package (CSP)

3. Applications：

• Proximity detection

• Proximity sensing in

    *Mobile phones

    *Portable entertainment units

• Switch for medical applications

• Switch for use in explosive environments

• Vandal proof switches

• Transportation: Switches in or underupholstery, leather, handles, mats, and glass

• Buildings: switch in or under carpets, glass, or tiles

• Sanitary applications: use of standard metal sanitary parts (e.g. tap) as switch

• Hermetically sealed keys on a keyboard

PCF8883T/1 Evaluation Board