CAP1188-1-CP-TR Datasheet, PDF (53/93 Pages) Microchip Technology – 8 Channel Capacitive Touch Sensor with 8 LED Drivers

8 Channel Capacitive Touch Sensor with 8 LED Drivers
Datasheet
Table 5.18 AVG Bit Decode (continued)
AVG[2:0]
2
1
1
0
1
1
1
1
NUMBER OF SAMPLES TAKEN
0
PER MEASUREMENT
1
32
0
64
1
128
Bits 3 - 2 - SAMP_TIME[1:0] - Determines the time to take a single sample as shown in Table 5.19.
Table 5.19 SAMP_TIME Bit Decode
SAMP_TIME[1:0]
1
0
0
0
0
1
1
0
1
1
SAMPLE TIME
320us
640us
1.28ms (default)
2.56ms
Bits 1 - 0 - CYCLE_TIME[1:0] - Determines the overall cycle time for all measured channels during
normal operation as shown in Table 5.20. All measured channels are sampled at the beginning of the
cycle time. If additional time is remaining, then the device is placed into a lower power state for the
remaining duration of the cycle.
Table 5.20 CYCLE_TIME Bit Decode
CYCLE_TIME[1:0]
1
0
OVERALL CYCLE TIME
0
0
35ms
0
1
70ms (default)
1
0
105ms
1
1
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 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.
SMSC CAP1188
53
DATASHEET
Revision 1.32 (01-05-12)