3 Channel Capacitive Touch Sensor with 3 LED Drivers
Datasheet
Chapter 4 General Description
The CAP1133 is a multiple channel Capacitive Touch sensor with multiple power LED drivers. It
contains three (3) individual capacitive touch sensor inputs with programmable sensitivity for use in
touch sensor applications. Each sensor input automatically recalibrates to compensate for gradual
environmental changes.
The CAP1133 also contains three (3) low side (or push-pull) LED drivers that offer full-on / off, variable
rate blinking, dimness controls, and breathing. Each of the LED drivers may be linked to one of the
sensor inputs to be actuated when a touch is detected. As well, each LED driver may be individually
controlled via a host controller.
The CAP1133 offers multiple power states. It operates at the lowest quiescent current during its Deep
Sleep state. In the low power Standby state, it can monitor one or more channels and respond to
communications normally.
The device communicates with a host controller using SMBus / I2C. The host controller may poll the
device for updated information at any time or it may configure the device to flag an interrupt whenever
a touch is detected on any sensor pad.
A typical system diagram is shown in Figure 4.1.
VDD
Embedded Controller
3.3V – 5V
Touch
Button
CS1
CS2
CS3
LED1
LED2
LED3
CAP1133
Touch
Button
Touch
Button
Figure 4.1 System Diagram for CAP1133
Revision 1.32 (01-05-12)
SMSC CAP1133
DATA1S8HEET
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