8 Channel Capacitive Touch Sensor with 2 LED Drivers
Datasheet
Table 5.60 LED Duty Cycle Decode (continued)
X_MAX/MIN_DUTY [3:0]
MAXIMUM DUTY
CYCLE
MINIMUM DUTY
CYCLE
3
2
1
0
1
1
1
1
1
1
0
0
1
1
1
1
1
1
0
0
1
1
0
1
0
1
0
1
40%
46%
53%
63%
77%
100%
35%
40%
46%
53%
63%
77%
5.37
LED Direct Ramp Rates Register
Table 5.61 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 behavior mode. 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 5.62.
Bits 2 - 0 - FALL_RATE[2:0] - Determines the falling edge time of an LED when it transitions from its
maximum drive state to its minimum drive state as shown in Table 5.62.
Table 5.62 Rise / Fall Rate Decode
RISE_RATE/ FALL_RATE/ BIT DECODE
2
1
0
RISE / FALL TIME (TRISE / TFALL))
0
0
0
0
1
1
0
0
1
1
0
0
0
1
0
1
0
1
0
250ms
500ms
750ms
1s
1.25s
Revision 1.32 (01-05-12)
SMSC CAP1128
DATA7S6HEET
SMSC [ SMSC CORPORATION ]
