Capacitive Switches

The MS888X-series are ultra-low-power capacitive touch and proximity sensors. The devices below are dynamic switches using a single electrode. The finger approaches the electrode, touches or is close and then the finger leaves. The event is detected when the circuit leaves its equilibrium state due to a change in the capacitance close to the electrode. Slow changes of capacitance caused by manufacturing tolerances, dirt or water are compensated. They are suitable for battery applications where the event is dynamic.

 

Applications

• Medical
• Automotive
• Buildings & Sanitary
• Mobile application
• Hermetical or vandal proof switches
• Intrinsic safety

 

General Features

• Dynamic proximity switch
• Digital processing method
• Automatic calibration
• Open-drain output (P-type MOSFET, external load between pin and ground)
• Low-power battery operation possible
• Adjustable response time
• Adjustable sensitivity
• Output configurable as push-button, toggle or pulse
• Large voltage operating range
• Internal voltage regulator
• Large operating temperature range (-40°C to 85°C)

 

Type specific properties

1- and 2-channel:

• Configurable output
• Large voltage operating range (VHI = 3 to 9V)

8-channel:

• Keypad, matrix and slider applications up to 8x8 matrix (2 chips cascaded)
• Unrivalled current consumption, typically 10uA
• Fast-mode Plus (Fm+) I2C-Interface with interrupt generation
• Sleep mode <100nA
   

Overview