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Baseline Increment
Fast tracking if DATA
n
is
negative
Button Pressed
Button Released
Baseline
DATA
n
Figure 8-9. Baseline Tracking in the Presence of a Button Press
The baseline tracking for a particular channel can be paused when the channel output is asserted. This is
achieved by setting the corresponding BTPAUSE bit in
Register BTPAUSE_MAXWIN (Address 0x16)
to b1.
If DATA
n
is negative, the tracking speed will be scaled by the fast tracking factor as specified in
Registers FTF0
(Address 0x25)
,
FTF1_2 (Address 0x28)
, or
FTF3 (Address 0x2B)
.
shows the scaling factors for
various FTF
n
settings.
BINC (DATA
n
< 0) = Fast_Tracking_Factor_
n
× BINC (DATA
n
> 0)
(14)
Table 8-2. Fast Tracking Factor Settings
FTFn Setting
Fast Tracking Factor
b00
1
b01
4
b10
8
b11
16
Note
When the continuous sampling rate using NPCS bit is set, the baseline tracking increment is a fixed
value.
8.1.10 Mitigating False Button Detections
The LDC3114 offers several algorithms that can mitigate false button detections due to mechanical non-idealities
associated with groups of buttons. These are listed below.
8.1.10.1 Eliminating Common-Mode Change (Anti-Common)
This algorithm eliminates false detection when a user presses the middle of two or more buttons, which could
lead to a common-mode response on multiple buttons. All the buttons can be individually enabled to have this
feature by programming
Register COMMON_DEFORM (Address 0x1A)
.
SNOSDD0 – DECEMBER 2021
44
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