CapSense Design Tools
CY8C20xx7/S CapSense
®
Design Guide
Doc. No. 001-78329 Rev. *E
28
Figure 3-9. Signal Values for Different Conversion Gains
raw count
C
X
C
P
C
P
+C
F
C
F
maximum raw count = 2
N
Signal 2
0
G
C2
G
C1
Signal 1
Baseline 1
Baseline 2
G
C3
G
C3
> G
C2
> G
C1
shows three plots corresponding to three conversion gain values G
C3
, G
C2
, and G
C1
. An increase in the
conversion gain results in a higher signal value. However, this increase in the conversion gain also moves the raw
count corresponding to C
P
towards the maximum value of raw count (2
N
). For very high gain values, the raw count
saturates as the plot of G
C3
shows. Therefore, you should tune the conversion gain to get a good signal value while
avoiding a saturation of raw count. It is recommended to tune the gain such that the raw count corresponding to C
P
is
85 percent of the maximum raw count, as
Figure 3-10. Recommended Tuning if I
COMP
is Zero
raw count
C
X
C
P
C
P
+C
F
C
F
maximum raw count = 2
N
85 % of maximum
raw count
Signal
0
G
C
This parameter can be changed at runtime using the corresponding API function.
Possible values are 1 to 127.
