Datasheet

8 Channel Capacitive Touch Sensor with 8 LED Drivers
Datasheet
SMSC CAP1188 41 Revision 1.32 (01-05-12)
DATASHEET
During Power-On-Reset (POR), the default values are stored in the registers. A POR is initiated when
power is first applied to the part and the voltage on the VDD supply surpasses the POR level as
specified in the electrical characteristics. Any reads to undefined registers will return 00h. Writes to
undefined registers will not have an effect.
When a bit is “set”, this means that the user writes a logic ‘1’ to it. When a bit is “cleared”, this means
that the user writes a logic ‘0’ to it.
5.1 Main Control Register
The Main Control register controls the primary power state of the device.
Bits 7 - 6 - GAIN[1:0] - Controls the gain used by the capacitive touch sensing circuitry. As the gain is
increased, the effective sensitivity is likewise increased as a smaller delta capacitance is required to
generate the same delta count values. The sensitivity settings may need to be adjusted along with the
gain settings such that data overflow does not occur.
APPLICATION NOTE: The gain settings apply to both Standby and Active states.
B9h
R Sensor Input
Calibration LSB 1
Stores the 2 LSBs of the calibration
value for sensor inputs 1 - 4
00h Page 83
BAh
R Sensor Input
Calibration LSB 2
Stores the 2 LSBs of the calibration
value for sensor inputs 5 - 8
00h Page 83
FDh R Product ID
Stores a fixed value that identifies
each product
50h Page 83
FEh R Manufacturer ID
Stores a fixed value that identifies
SMSC
5Dh Page 84
FFh R Revision
Stores a fixed value that represents
the revision number
83h Page 84
Table 5.2 Main Control Register
ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT
00h R/W Main Control GAIN[1:0] STBY DSLEEP - - - INT 00h
Table 5.3 GAIN Bit Decode
GAIN[1:0]
CAPACITIVE TOUCH SENSOR GAIN1 0
0 0 1
0 1 2
1 0 4
1 1 8
Table 5.1 Register Set in Hexadecimal Order (continued)
REGISTER
ADDRESS R/W REGISTER NAME FUNCTION
DEFAULT
VALUE PAGE