8 Channel Capacitive Touch Sensor with 8 LED Drivers
Datasheet
Bit 6 - LED7_POL - Determines the polarity of the LED7 output.
Bit 5 - LED6_POL - Determines the polarity of the LED6 output.
Bit 4 - LED5_POL - Determines the polarity of the LED5 output.
Bit 3 - LED4_POL - Determines the polarity of the LED4 output.
Bit 2 - LED3_POL - Determines the polarity of the LED3 output.
Bit 1 - LED2_POL - Determines the polarity of the LED2 output.
Bit 0 - LED1_POL - Determines the polarity of the LED1 output.
5.26 LED Output Control Register
Table 5.40 LED Output Control Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
LED Output
Control
LED8_
DR
LED7_
DR
LED6_
DR
LED5_
DR
LED4_
DR
LED3_
DR
LED2_
DR
LED1_
DR
74h
R/W
00h
The LED Output Control Register controls the output state of the LED pins.
All LEDs that are associated with a Capacitive Touch Sensor channel are automatically enabled and
will be actuated per the LED Behavior.
For those LEDs that are not linked with a Capacitive Touch Sensor channel, then the bit state
determines whether the LED is actuated or not actuated.
The LED Polarity Control register will determine the non actuated state of the LED pins.
Table 5.41 shows the interaction between the polarity controls, output controls and relative brightness.
Table 5.41 LED Polarity Behavior
LED
OUTPUT
CONTROL
REGISTER
LED
BEHAVIORS
LED
APPEARANCE
POLARITY
MAX DUTY
MIN DUTY
BRIGHTNESS
maximum % of
time that the LED
is on (logic 0)
minimum % of
time that the LED
is on (logic 0)
maximum brightness at
minimum duty cycle
on at minimum
duty cycle
0
1
0
1
inverted
off
on
off
on
maximum % of
time that the LED
is on (logic 0)
minimum % of
time that the LED
is on (logic 0)
maximum brightness at
max duty cycle. Brightness
ramps from min to max
according to
LED behavior
inverted
maximum % of
time that the LED
is off (logic 1)
minimum % of
time that the LED
is off (logic 1)
on at 100 - min
duty cycle
non-
inverted
maximum brightness at 100
- min duty cycle
(Note 5.3)
maximum % of
time that the LED
is off (logic 1)
minimum % of
time that the LED
is off (logic 1)
maximum brightness at 100
- min duty cycle. Brightness
ramps from max to min
non-
inverted
according to
LED behavior
Note 5.3 For example: when polarity is non-inverted, if min duty cycle is 0, then the LED would be
at logic 1 (off) 0% of the time. It will be at logic 0 (on), 100% of the time (100 - min duty
cycle).
Revision 1.1 (08-05-09)
SMSC CAP1088
DATA5S6HEET