CAP1005 datasheet(44/53 Pages) SMSC

44 / 53 page

5 and 6 Channel Capacitive Touch Sensor

Datasheet

Revision 1.1 (08-05-09)

SMSC CAP1005 / CAP1006

DATASHEET

Bit 2 - STBY SAMP_TIME - Determines the time to take a single sample when the device is in Standby.

‘0’ - The sampling time is ~2.56ms.

‘1’ (default) - The sampling time is ~1.28ms.

Bits 1 - 0 - STBY_CY_TIME[2:0] - Determines the overall cycle time for all measured channels during

normal operation as shown in Table 5.17. 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.

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.

Table 5.31 STBY_AVG Bit Decode

STBY_AVG[2:0]

NUMBER OF SAMPLES TAKEN

PER MEASUREMENT

8 (default)

128

Table 5.32 STBY_CY_TIME Bit Decode

STBY_CY_TIME[1:0]

OVERALL CYCLE TIME

35ms

70ms (default)

105ms

140ms

CAP1005 Datasheet(PDF) 44 Page - SMSC Corporation