Glossary
AN66308 - CY8CMBR2044 CapSense® Design Guide, Doc. No. 001-66308 Rev. *F
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Scan Time
Time taken for completing the scan of a sensor.
Self-Capacitance
The capacitance associated with an electrode with respect to circuit ground.
Sensitivity
The change in Raw Count corresponding to the change in sensor capacitance, expressed in counts/pF.
Sensitivity of a sensor is dependent on the board layout, overlay properties, sensing method, and tuning
parameters.
Sense Clock
A clock source used to implement a switched-capacitor front-end for the CSD sensing method.
Sensor
Sensor Auto Reset
A setting to prevent a sensor from reporting false touch status indefinitely due to system failure, or when a
metal object is continuously present near the sensor.
When Sensor Auto Reset is enabled, the Baseline is always updated even if the Difference Count is
greater than the Noise Threshold. This prevents the sensor from reporting the ON status for an indefinite
period of time. When Sensor Auto Reset is disabled, the Baseline is updated only when the Difference
Count is less than the Noise Threshold.
Sensor Ganging
Shield Electrode
Copper fill around sensors to prevent false touches due to the presence of water or other liquids. Shield
Electrode is driven by the shield signal output from the CSD block. See
Shield Tank Capacitor (C
SH
)
An optional external capacitor (C
SH
Tank Capacitor) used to enhance the drive capability of the CSD
shield, when there is a large shield layer with high parasitic capacitance.
Signal (CapSense Signal)
Difference Count is also called Signal. See Difference Count.
Signal-to-Noise Ratio (SNR)
The ratio of the sensor signal, when touched, to the noise signal of an untouched sensor.
Slider Resolution
A parameter indicating the total number of finger positions to be resolved on a slider.
Touchpad
A Widget consisting of multiple sensors arranged in a specific horizontal and vertical fashion to detect the
X and Y position of a touch.
Trackpad
Tuning
