LM3561 Datasheet, PDF (25/36 Pages) Texas Instruments – LM3561 Synchronous Boost Converter with 600mA High Side LED Driver and I 2 C-Compatible Interface

GPIO REGISTER (ADDRESS 0x20)
The GPIO register contains the control bits which change the state of the TX1/TORCH/GPIO1 pin and the TX2/GPIO2 pin to general
purpose I/O’s (GPIO’s).
Bit 7
Not Used
N/A
TABLE 4. GPIO Register Bit Settings
Bit 6
Bit 5
TX2/GPIO2/ TX2/GPIO2
INT Interrupt data
Output
0 = INT mode This bit is the
is disabled
(default)
read or write
data for TX2/
1 = When TX2/ GPIO2 in
GPIO2 is
GPIO mode
configured as (default is 0)
a GPIO output
TX2/GPIO2/
INT is set for
INT mode and
will pull low
when either
the LED
Thermal Fault
Flag is set or
the VIN
Monitor Flag is
set
Bit 4
TX2/GPIO2
data direction
0 = TX2/
GPIO2 is a
GPIO Input
(default)
1 = TX2/
GPIO2 is a
GPIO Output
Bit 3
TX2/GPIO2
Control
Bit 2
TX1/GPIO1
data
0 = TX2/
This bit is the
GPIO2 is a read or write
flash interrupt data for TX1/
input (default) GPIO1 in
1 = TX2/
GPIO mode
GPIO2 is
(default is 0)
configured as
a GPIO
Bit 1
TX1/GPIO1
data direction
0 = TX1/
GPIO1 is a
GPIO input
(default)
1 = TX1/
GPIO1 is a
GPIO output
Bit 0
TX1/GPIO1
Control
0 = TX1/
GPIO1 is
configured as
flash interrupt
input(default)
1 = TX1/
GPIO1 is
configured as
a GPIO
VIN MONITOR REGISTER (ADDRESS 0X80)
The VIN Monitor Register controls the on/off state of the VIN Monitor comparator as well as selects the 4 programmable thresholds.
TABLE 5. VIN Monitor Register Bit Settings
Bits [7:3]
Not Used
N/A
Bits [2:1]
VIN Monitor Threshold Settings
00 = 2.9V threshold (V_IN falling)
Default
01=3.0V threshold (V_IN falling)
10 = 3.1V threshold (V_IN falling)
11 = 3.2V threshold (V_IN falling)
Bit 0
VIN Monitor Enable
0 = VIN Monitor Comparator is
disabled (default)
1 = VIN Monitor Comparator is
enabled.
TORCH BRIGHTNESS REGISTER (0XA0)
The Torch Brightness Register contains the bits to program the LED current in Torch Mode.
Bits [7:3]
Not Used
N/A
TABLE 6. Torch Brightness Register Bit Settings
Bits [2:0]
Torch Current Settings
000 = 18mA
001 = 36.8mA
010 = 55.6mA (default)
011 = 74.4mA
100 = 93.2mA
101 = 112mA
110 = 130.8mA
111 = 149.6mA
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