sx8638 Semtech Corporation, sx8638 Datasheet - Page 54

• Manufacturer Part Number: sx8638
• Description: Low Power, Capacitive Button And Slider Touch Controller 8 Sensors With Enhanced Led Drivers And Proximity
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & SENSING
The maximum position (SldPosMax) is defined by:
Slow varying slider ticks due to environmental changes are handled as buttons in the previous section.
If the ticks pass below the slider negative threshold for more than the compensation negative max counter then an
offset compensation phase will be triggered.
If the ticks pass above the slider average positive threshold then the averaging filters will be held.
A finger that moves very slowly over the slider is not considered as a movement. The status move low and move
high will not be set.
A finger that moves faster on the slider will change the movement status.
A movement is detected if the difference of the position for two succeeding samples at the scanning rate goes
beyond the movement threshold (SldMoveThresh). A large movement threshold requires very rapid finger
movements, while a small movement threshold detects more easily movements but gets sensitive to noise
variations as well.
Revision 7_6, September 10
with:
N is the number of sensors in the slider
SldPosMax
=
© 2010 Semtech Corp.
Low Power, Capacitive Button and Slider Touch Controller
SldNorm
32
(8 sensors) with Enhanced LED Drivers and Proximity
54
×
(
N
−
1
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DATASHEET
www.semtech.com
SX8638