3 Channel Capacitive Touch Sensor with 3 LED Drivers
Datasheet
Bit 6 - ALT_POL - Determines the ALERT# pin polarity and behavior.
‘0’ - The ALERT# pin is active high and push-pull.
‘1’ (default) - The ALERT# pin is active low and open drain.
Bit 5 - BLK_PWR_CTRL - Determines whether the device will reduce power consumption while waiting
between conversion time completion and the end of the polling cycle.
‘0’ (default) - The device will always power down as much as possible during the time between the
end of the last conversion and the end of the polling cycle.
‘1’ - The device will not power down the Cap Sensor during the time between the end of the last
conversion and the end of the polling cycle.
Bit 4 - BLK_POL_MIR - Determines whether the LED Mirror Control register bits are linked to the LED
Polarity bits. Setting this bit blocks the normal behavior which is to automatically set and clear the LED
Mirror Control bits when the LED Polarity bits are set or cleared.
‘0’ (default) - When the LED Polarity controls are set, the corresponding LED Mirror control is
automatically set. Likewise, when the LED Polarity controls are cleared, the corresponding LED
Mirror control is also cleared.
‘1’ - When the LED Polarity controls are set, the corresponding LED Mirror control is not
automatically set.
Bit 3 - SHOW_RF_NOISE - Determines whether the Noise Status bits will show RF Noise as the only
input source.
‘0’ (default) - The Noise Status registers will show both RF noise and low frequency EMI noise if
either is detected on a capacitive touch sensor input.
‘1’ - The Noise Status registers will only show RF noise if it is detected on a capacitive touch sensor
input. EMI noise will still be detected and touches will be blocked normally; however, the status bits
will not be updated.
Bit 2 - DIS_RF_NOISE - Determines whether the RF noise filter is enabled. Setting this bit disables
the feature.
‘0’ (default) - If RF noise is detected by the analog block, the delta count on the corresponding
channel is set to 0. Note that this does not require that Noise Status bits be set.
‘1’ - A touch is not blocked even if RF noise is detected.
Bit 0 - INT_REL_n - Controls the interrupt behavior when a release is detected on a button.
‘0’ (default) - An interrupt is generated when a press is detected and again when a release is
detected and at the repeat rate (if enabled - see Section 5.13).
‘1’ - An interrupt is generated when a press is detected and at the repeat rate but not when a
release is detected.
5.7
Sensor Input Enable Registers
Table 5.11 Sensor Input Enable Registers
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
Sensor Input
Enable
21h
R/W
-
-
-
-
-
CS3_EN
CS2_EN
CS1_EN
07h
The Sensor Input Enable registers determine whether a capacitive touch sensor input is included in
the sampling cycle. The length of the sampling cycle is not affected by the number of sensor inputs
measured.
Revision 1.32 (01-05-12)
SMSC CAP1133
DATA3S2HEET
SMSC [ SMSC CORPORATION ]
