Multiple Channel Capacitive Touch Sensor and LED Driver
Datasheet
Bits 3 - 0 - LED_X_MIN_DUTY[3:0] - Determines the minimum PWM duty cycle for the LED drivers
as shown in Table 5.67.
Table 5.67 LED Duty Cycle Decode
LED_X_MAX/MIN_DUTY [3:0]
3
2
1
0
DUTY CYCLE
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0%
12.5%
18.75%
25.0%
31.25%
37.5%
43.75%
50.0%
56.25%
62.5%
68.75%
75.0%
81.25%
87.5%
93.75%
100%
5.46 LED Direct Ramp Rates Register
Table 5.68 LED Direct Ramp Rates Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
LED Direct
Ramp Rates
94h
R/W
-
-
RISE_RATE[2:0]
FALL_RATE[2:0]
00h
The LED Direct Ramp Rates register control the rising and falling edge time of an LED that is
configured to operate in Direct mode and is linked to a Capacitive Touch sensor. The rising edge time
corresponds to the amount of time the LED takes to transition from its minimum duty cycle to its
maximum duty cycle. Conversely, the falling edge time corresponds to the amount of time that the LED
takes to transition from its maximum duty cycle to its minimum duty cycle.
Bits 5 - 3 - RISE_RATE[2:0] - Determines the rising edge time of an LED when it transitions from its
minimum drive state to its maximum drive state as shown in Table 5.69.
Revision 1.65 (08-11-09)
SMSC CAP1014
DATA7S4HEET
SMSC [ SMSC CORPORATION ]
