MAX6947 Maxim Integrated Products, MAX6947 Datasheet - Page 10

• Manufacturer Part Number: MAX6947
• Description: Constant-Current LED Drivers and I/O Expanders
• Manufacturer: Maxim Integrated Products

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The global-current register sets the full (maximum) con-
stant-current sink into an I/O port configured as an out-
put (Table 5). Each output port’s individual constant-
current sink can set to either half or full scale of the
global current by the output-current registers (Table 6).
By default, maximum current is 20mA, hence the default
maximum half current is 10mA.
Set each output port’s individual constant-current sink
to either half scale or full scale of the global current.
Table 5. Global-Current Register Format (0x15)
Table 6. Output-Current Register Format
10-Port, Constant-Current LED Drivers and
I/O Expanders with PWM Intensity Control
10
Full current is 2.5mA; half current is 1.25mA
Full current is 5mA; half current is 2.5mA
Full current is 7.5mA; half current is 3.75mA
Full current is 10mA; half current is 5mA
Full current is 12.5mA; half current is 6.25mA
Full current is 15mA; half current is 7.5mA
Full current is 17.5mA; half current is 8.75mA
Full current is 20mA; half current is 10mA
Output P0 is set to half constant current
Output P0 is set to full constant current
Output P1 is set to half constant current
Output P1 is set to full constant current
Output P2 is set to half constant current
Output P2 is set to full constant current
Output P3 is set to half constant current
Output P3 is set to full constant current
Output P4 is set to half constant current
Output P4 is set to full constant current
Output P5 is set to half constant current
Output P5 is set to full constant current
Output P6 is set to half constant current
Output P6 is set to full constant current
Output P7 is set to half constant current
Output P7 is set to full constant current
Output P8 is set to half constant current
Output P8 is set to full constant current
Output P9 is set to half constant current
Output P9 is set to full constant current
______________________________________________________________________________________
DESCRIPTION
DESCRIPTION
Ports Configured as Outputs
CODE (HEX)
ADDRESS
0x13
0x14
D7
X
X
X
X
X
X
X
X
D7
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
D6
X
X
X
X
X
X
X
X
Use the output-current registers to set the individual
currents (Table 6). Set the global current by the global-
current register (Table 5).
Set each output current individually to best suit the
maximum operating current of an LED load, or even
adjust on the fly to double the effective intensity control
range of each output. The individual current selection is
10mA (half) or 20mA (full) when setting the global-cur-
rent register to its maximum value.
D6
X
X
X
X
X
X
X
X
X
X
X
X
0
1
X
X
X
X
X
X
D5
X
X
X
X
X
X
X
X
D5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
REGISTER BIT
D4
X
X
X
X
X
X
X
X
REGISTER BIT
D4
X
X
X
X
X
X
X
X
0
1
X
X
X
X
X
X
X
X
X
X
D3
X
X
X
X
X
X
X
X
D3
X
X
X
X
X
X
0
1
X
X
X
X
X
X
X
X
X
X
X
X
D2
0
0
0
0
1
1
1
1
D2
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
D1
0
0
1
1
0
0
1
1
D1
X
X
0
1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
D0
D0
0
1
0
1
0
1
0
1
0
1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
X
X