Datasheet

CY8C20xx6A/H CapSense Design Guide Doc. No. 001-65973 Rev. *A 29
4.2 Tuning the CSA_EMC User Module
Manual selection of iDAC settings is not required for the CSA_EMC User Module; they are adjusted automatically.
However, monitoring the iDAC settings can be useful for debugging or statistical process control.
4.2.1 Clock and Settling Time
The first step in tuning CSA_EMC User Module is to determine the settings for the clock and settling time. Figure 4-4
outlines the steps required to set these parameters.
Figure 4-4. Determining CSA_EMC Clock and Settling Times
Begin
Initial Settings
C
MOD
= 1 nF
Clock = IMO/8
Measure iDAC Gain,
iDAC
GAIN MEASURED
Read SA
code
SA
code
≤ 255 * (280/iDAC
GAIN MEASURED
)
Decrease CPU
Frequency
Estimate C
P
Estimate Settling Time,
t
settling,min
t
settling,min
/ (25 * t
cpu_clk
) ≤ 255
Reduce C
P
or Clock
End
No
No
Yes
Yes