8 Channel Capacitive Touch Sensor with 2 LED Drivers
Datasheet
Bit 3-2 - STBY SAMP_TIME[1:0] - Determines the time to take a single sample when the device is in
Standby as shown in Table 5.38.
Table 5.38 STBY_SAMP_TIME Bit Decode
STBY_SAMP_TIME[1:0]
1
0
SAMPLING TIME
0
0
1
1
0
1
0
1
320us
640us
1.28ms (default)
2.56ms
Bits 1 - 0 - STBY_CY_TIME[2:0] - Determines the overall cycle time for all measured channels during
standby operation as shown in Table 5.39. All measured channels are sampled at the beginning of the
cycle time. If additional time is remaining, the device is placed into a lower power state for the
remaining duration of the cycle.
Table 5.39 STBY_CY_TIME Bit Decode
STBY_CY_TIME[1:0]
1
0
OVERALL CYCLE TIME
0
0
1
1
0
1
0
1
35ms
70ms (default)
105ms
140ms
APPLICATION NOTE: The programmed cycle time is only maintained if the total averaging time for all samples is
less than the programmed cycle. The STBY_AVG[2:0] bits will take priority so that if more
samples are required than would normally be allowed during the cycle time, the cycle time
will be extended as necessary to accommodate the number of samples to be measured.
5.22
Standby Sensitivity Register
Table 5.40 Standby Sensitivity Register
ADDR
R/W
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
Standby
Sensitivity
42h
-
-
-
-
-
STBY_SENSE[2:0]
02h
The Standby Sensitivity register controls the sensitivity for sensor inputs that are active in Standby.
Bits 2 - 0 - STBY_SENSE[2:0] - Controls the sensitivity for sensor inputs that are active in Standby.
The sensitivity settings act to scale the relative delta count value higher or lower based on the system
parameters. A setting of 000b is the most sensitive while a setting of 111b is the least sensitive. At the
Revision 1.32 (01-05-12)
SMSC CAP1128
DATA6S2HEET
SMSC [ SMSC CORPORATION ]
