Datasheet
CY8C20xx6A/H CapSense Design Guide Doc. No. 001-65973 Rev. *A 3
Contents
1. Introduction .................................................................................................................................................................... 6
1.1
How to Use This Document ................................................................................................................................... 6
1.2 CY8C20xx6A/H CapSense Family Features ......................................................................................................... 6
1.3
Document Revision History ................................................................................................................................... 7
1.4 Document Conventions ......................................................................................................................................... 7
2.
CapSense Technology .................................................................................................................................................. 8
2.1 CapSense Equivalent Model ................................................................................................................................. 8
2.2
CapSense Capacitive Sensing Methods ............................................................................................................... 8
2.2.1
Capacitance Conversion ........................................................................................................................... 9
2.2.2
CapSense with Sigma Delta Modulator (CSD) ....................................................................................... 10
2.2.3 CapSense Successive Approximation Electromagnetic Compatible (CSA_EMC) .................................. 11
2.2.4
SmartSense™ Auto-Tuning .................................................................................................................... 12
3. CapSense Design Tools .............................................................................................................................................. 14
3.1
Overview ............................................................................................................................................................. 14
3.1.1
PSoC Designer and User Modules ......................................................................................................... 14
3.1.2
Universal CapSense Controller Kit ......................................................................................................... 15
3.1.3 Universal CapSense Controller Module Board ....................................................................................... 15
3.2
User Module Overview ........................................................................................................................................ 16
3.3
CapSense User Module Global Arrays ................................................................................................................ 17
3.3.1
Raw Count .............................................................................................................................................. 17
3.3.2
Baseline .................................................................................................................................................. 17
3.3.3 Difference Count ..................................................................................................................................... 18
3.3.4
Sensor State ........................................................................................................................................... 18
3.4 High-Level Parameters ........................................................................................................................................ 18
3.4.1
Finger Threshold ..................................................................................................................................... 18
3.4.2 Hysteresis ............................................................................................................................................... 19
3.4.3
Debounce ............................................................................................................................................... 19
3.4.4 Noise Threshold ...................................................................................................................................... 19
3.4.5
Baseline Update Threshold .................................................................................................................... 19
3.4.6 Negative Noise Threshold ...................................................................................................................... 20
3.4.7
Low Baseline Reset ................................................................................................................................ 20
3.4.8 Sensors Autoreset .................................................................................................................................. 20
3.4.9
High-Level Parameter Recommendations .............................................................................................. 20