8 Channel Capacitive Touch Sensor with 2 LED Drivers
Datasheet
Table 1.1 Pin Description for CAP1128 (continued)
PIN
NUMBER
UNUSED
CONNECTION
PIN NAME
PIN FUNCTION
PIN TYPE
SMDATA - Bi-directional, open-drain SMBus data -
requires pull-up resistor
DIOD (5V)
BC_DATA - Bi-directional, open-drain BC-Link data -
requires pull-up resistor
SMDATA /
BC_DATA /
SPI_MSIO /
SPI_MISO
DIO
DIO
DO
3
n/a
n/a
SPI_MSIO - SPI Master-Slave-In-Out bidirectional port
when used in bi-directional mode
SPI_MISO - SPI Master-In-Slave-Out port when used in
normal mode
SMCLK - SMBus clock input - requires pull-up resistor
BC_CLK - BC-Link clock input
DI (5V)
DI (5V)
DI (5V)
SMCLK /
BC_CLK /
SPI_CLK
4
5
SPI_CLK - SPI clock input
Connect to
Ground
N/C
Not Internally Connected
n/a
Connect to
Ground
Open drain LED 1 driver (default)
OD (5V)
6
7
LED1
leave open or
connect to
Ground
Push-pull LED 1 driver
Open drain LED 2 driver (default)
Push-pull LED 2 driver
DO
OD (5V)
DO
Connect to
Ground
LED2
leave open or
connect to
Ground
Connect to
Ground
8
9
N/C
Not Internally Connected
n/a
DI (5V)
OD (5V)
DO
Active high soft reset for system - resets all registers to
default values. If not used, connect to ground.
Connect to
Ground
RESET
ALERT# - Active low alert / interrupt output for SMBus
alert or SPI interrupt
Connect to
Ground
ALERT# - Active high push-pull alert / interrupt output
for SMBus alert or SPI interrupt
leave open
ALERT# /
BC_IRQ#
10
Connect to
Ground
BC_IRQ# - Active low interrupt / optional for BC-Link
OD (5V)
DO
BC_IRQ# - Active high push-pull interrupt / optional for
BC-Link
leave open
n/a
Address / communications select pin - pull-down
resistor determines address / communications
mechanism
11
12
ADDR_COMM
CS8
AI
Connect to
Ground
Capacitive Touch Sensor Input 8
AIO
SMSC CAP1128
Revision 1.32 (01-05-12)
DATAS11HEET
SMSC [ SMSC CORPORATION ]
