Multiple Channel Capacitive Touch Sensor and LED Driver
Datasheet
4.2
4.3
RESET Pin
The RESET pin is an active high reset that is driven from an external source. While it is asserted high,
all the internal blocks will be held in reset including the SMBus. All configuration settings will be reset
to default states and all readings will be cleared. Once the RESET pin is pulled low, the CAP1014 will
begin operation as if a power-on-reset had occurred.
LED Drivers
The CAP1014 contains eleven (11) LED Drivers. Each LED Driver is controlled independently of the
others and may be linked to the corresponding Capacitive Touch Sensor inputs. In addition, LED
drivers 1 - 8 can be configured to operate in one of the following modes with either push-pull or open-
drain drive. LED drivers 9 - 11 will only operate in as an open-drain driver.
1. Direct - The LED is configured to be on or off when the corresponding button is pressed or not
pressed. The dimness of both “on” states and “off” states can be programmed as well as the rising
and falling ramp times and delay when the corresponding button is released
2. Breathe - The LED is configured to breathe. Over the course of the programmed cycle the LED
will transition from the programmed minimum to the programmed maximum and then back off
again. This mode operates independently of any stimuli or may be linked so that the LED breathes
when the stimuli is asserted (or deasserted). This feature is commonly used for power LEDs when
in standby mode.
3. Pulse - The LED is configured to breathe 5 times with a programmable rate and dimness controls.
This mode is linked to a button press detection or release.
LED11 operates differently than the other LED outputs in three ways. First, it is configured to drive up
to two external LED channels simultaneously. Second, it is not disabled during the Sleep or Deep
Sleep modes of operation (see Section 5.1) and allows for different behaviors when the device is in
Fully Active Mode versus when the device is in Sleep or Deep Sleep mode.
4.3.1
Linking LEDs to Capacitive Touch Sensors
LEDs 1 - 7 can be optionally linked to Capacitive Touch Sensors 1-7 so that when the sensor detects
a button press, the corresponding LED will be actuated at one of the programmed responses.
4.4
Capacitive Touch Sensing
The CAP1014 contains 14 independent Capacitive Touch Sensor inputs. Each sensor has dynamic
range to detect a change of capacitance due to a touch. Additionally, each sensor can be configured
to be automatically and routinely re-calibrated.
4.4.1
Multiple Button Presses
If multiple sensor buttons (with a programmable threshold - see Section 5.23) are simultaneously
detected, then only the first N buttons that are detected are flagged. All other buttons are ignored.
Furthermore, the device remembers which buttons were legitimate so new touches are not detected
so long as N buttons are pressed.
Likewise, if too many (based on the programmed threshold - see Section 5.23) grouped sensor
presses are detected, then the device will block all press detections on the grouped buttons and cancel
any current presses as if the sensor had been released.
4.4.2
Lid Closure
To detect lid closure or other similar events, lid closure sensor thresholds can be set. A Lid Closure
Event can be flagged based on either a minimum number of sensors or on specific sensors
Revision 1.65 (08-11-09)
SMSC CAP1014
DATA2S2HEET
SMSC [ SMSC CORPORATION ]
