mpr084 Freescale Semiconductor, Inc, mpr084 Datasheet - Page 3

• Manufacturer Part Number: mpr084
• Description: Proximity Capacitive Touch Sensor Controller
• Manufacturer: Freescale Semiconductor, Inc

Sensors
Freescale Semiconductor
1.1.3
The following terms are used to describe front panel interface and capacitive touch sensor technology throughout this document.
Table 2. Terminology
Touch Sensor
Touch Sensor Controller
Key
Touch Pad
Solid Pad
Split Pad
N-key Lockout
N-key rollover
I
2
C
Terminology
Term
A Touch Sensor is the combination of a Touch Sensor Controller and a connected conductive area
referred to as an electrode.
A Touch Sensor Controller is the intelligent part of a Touch Sensor which measures capacitance and
differentiates between touched and untouched pads.
A Key or Switch is a mechanical device that makes an electrical connection only when pressed.
A Touch Pad is a type of capacitive sensor that is used for direct replacement of a Key. A capacitive
touch sensor determines touch state by differentiating between high and low capacitances. When
there is a change in the state this can be interpreted in the same way as a mechanical Key.
A Solid or Full Pad is a type of touch pad where exactly one electrode is used
A Split Pad is a type of touch pad where more than one electrode is used. Split Pads are used to
increase the total number of possible touch pads without increasing the electrical connections to the
Touch Sensor Controller.
N-Key Lockout refers to the logic that determines how many keys can be simultaneously touched in
a system. For example, 1-key lockout would only allow a single key to be touched before ignoring
all future touches.
N-Key Rollover refers to the logic that determines how many keys can be pressed in succession
without releasing previous keys. For example, a system with 1-key lockout and 2-key rollover would
allow 2-keys to be pressed in succession but would only report the second key once the first key
was released.
Inter-Integrated Circuit Communication
Definition
MPR084
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