Max6948b, Table 8. global-current register format (0x15), Table 9. output-current register format (0x13) – Rainbow Electronics MAX6948B User Manual
Page 15
High-Efficiency PWM LED Driver with Boost
Converter and Five Constant-Current GPIO Ports
15
MAX6948B
Ports Configured as Outputs
The global-current register sets the full (maximum)
constant-current sink amount for I/O ports configured as
an output (Table 8). Power-up sets the global current to
its maximum value.
Set each output port’s individual constant-current sink to
either half scale or full scale of the global current. Use
the output-current registers to set the individual currents
(Table 9). By default, P0 and P1 start up set to full cur-
rent, while P2, P3, and P4 are set to half current.
Set each output current individually to best suit the
maximum operating current of an LED load, or adjust as
needed to double the effective intensity control range of
each output. The maximum individual current selection is
15mA (half) or 30mA (full) for ports P0 and P1, and 5mA
(half) or 10mA (full) for ports P2, P3, and P4.
Table 8. Global-Current Register Format (0x15)
X = Don’t care.
Table 9. Output-Current Register Format (0x13)
REGISTER DESCRIPTION
REGISTER DATA
D7
D6
D5
D4
D3
D2
D1
D0
RESERVED
GLOBAL CURRENT
3.75mA full-current value (P0, P1)
1.25mA full-current value (P2, P3, P4)
X
X
X
X
X
0
0
0
7.5mA full-current value (P0, P1)
2.5mA full-current value (P2, P3, P4)
X
X
X
X
X
0
0
1
11.25mA full-current value (P0, P1)
3.75mA full-current value (P2, P3, P4)
X
X
X
X
X
0
1
0
15mA full-current value (P0, P1)
5mA full-current value (P2, P3, P4)
X
X
X
X
X
0
1
1
18.75mA full-current value (P0, P1)
6.25mA full-current value (P2, P3, P4)
X
X
X
X
X
1
0
0
22.5mA full-current value (P0, P1)
7.5mA full-current value (P2, P3, P4)
X
X
X
X
X
1
0
1
26.25mA full-current value (P0, P1)
8.75mA full-current value (P2, P3, P4)
X
X
X
X
X
1
1
0
30mA full-current value (P0, P1)
10mA full-current value (P2, P3, P4)
X
X
X
X
X
1
1
1
Power-up default
0
0
0
0
0
1
1
1
REGISTER BIT
DESCRIPTION
VALUE
FUNCTION
DEFAULT VALUE
D7, D6, D5
Reserved
0
—
0
D4
P4
0
Port P4 is set to half current
0
1
Port P4 is set to full current
D3
P3
0
Port P3 is set to half current
0
1
Port P3 is set to full current
D2
P2
0
Port P2 is set to half current
0
1
Port P2 is set to full current
D1
P1
0
Port P1 is set to half current
1
1
Port P1 is set to full current
D0
P0
0
Port P0 is set to half current
1
1
Port P0 is set to full current