User guide

Getting Started with CapSense Document No. 001-64846 Rev. *A 13
Figure 2-9. CSA_EMC Equivalent Circuit
The CSA_EMC CapSense algorithm has been enhanced to work well in the presence of RF interference. CSA_EMC
is used in applications where CapSense is exposed to conducted interference, AC noise, and other noise sources
such as inverters, transformers, and power supplies. Electromagnetic Compatibility (EMC) Considerations discusses
this topic in detail.
For an in-depth discussion of Cypress’s CSA_EMC sensing method refer to PSoC® CY8C20x66, CY8C20x66A,
CY8C20x46/96, CY8C20x46A/96A, CY8C20x36, CY8C20x36A Technical Reference Manual (TRM).
2.4 CapSense Tuning
Optimal CapSense system performance depends on board layout, button dimensions, overlay material and
application requirements. These factors are discussed in Design Considerations. In addition to these factors,
switching frequency and threshold levels must be carefully selected for robust and reliable performance. Tuning is the
process of determining the optimum values for these parameters. Tuning is required to maintain high sensitivity to
touch and to compensate for process variations in the sensor board, overlay material, and environmental conditions.