General Description
BU21181FS is a capacitive switch controller that detects
capacitance change and judges the operation of Switch
ON / OFF or Long Press. The function to prevent false
detection of water enables it to be used at places using
water.

Features
 18 Capacitive Sensor Pins
 Switch ON / OFF / Long Press Detection
 Inform Detection Results by Interrupt Pin
 Prevention False Detection by Water
 Noise Calibration Function
 Drift Calibration Function
 Adjust Sampling Period Function
 2-wire Serial Bus Interface
 Single Power Supply

Applications
 Home Appliance such as IH Cooker, Refrigerator and
Rice Cooker
 AV Appliance such as TV and HDD Recorder
 Office Automation Appliance such as Printer
 Electrical Equipment with Multiple Switches