Max6948b – Rainbow Electronics MAX6948B User Manual
Page 19
High-Efficiency PWM LED Driver with Boost
Converter and Five Constant-Current GPIO Ports
19
MAX6948B
Figure 4. Ramp-Up Behavior
Figure 5. Hold-Off and Ramp-Down Behavior
Table 11. Port Ramp-Down Register Format (0x11)
EXIT SHUTDOWN COMMAND
FULL CURRENT/
HALF CURRENT
0
1s
2s
1/4s 1/2s
1/8s
1/16s
ZERO TO 4s CURRENT RAMP-UP AFTER CS RUN
4s
ZERO TO 4s HOLD-OFF DELAY BEFORE RAMP-DOWN
ZERO TO 4s CURRENT RAMP-DOWN AFTER HOLD-OFF DELAY
1s
2s
4s
1s
2s
1/8s
1/16s
1/8s
1/16s
ZERO TO 8s CURRENT RAMP-DOWN
4s
1/4s 1/2s
1/4s 1/2s
FULL CURRENT/
HALF CURRENT
0
REGISTER DESCRIPTION
REGISTER DATA
D7
D6
D5
D4
D3
D2
D1
D0
RESERVED
HOLD-OFF
RAMP-DOWN
Immediately shuts down after hold-off delay
X
X
X
X
X
0
0
0
0.0655s ramp-down from full current after
hold-off delay
X
X
X
X
X
0
0
1
0.131s ramp-down from full current after
hold-off delay
X
X
X
X
X
0
1
0
0.262s ramp-down from full current after
hold-off delay
X
X
X
X
X
0
1
1
0.524s ramp-down from full current after
hold-off delay
X
X
X
X
X
1
0
0
1.049s ramp-down from full current after
hold-off delay
X
X
X
X
X
1
0
1
2.097s ramp-down from full current after
hold-off delay
X
X
X
X
X
1
1
0