SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
TRUTH TABLE
CLOCK
UP
UP
UP
DOWN
DOWN
LATCH
H
L
H
X
X
ENABLE
L
L
L
L
H
SERIAL-IN
D
n
D
n + 1
D
n + 2
D
n + 3
D
n + 3
OUT0 … OUT5 … OUT7
D
n
… D
n - 5
… D
n - 7
No change
D
n + 2
… D
n - 3
… D
n - 5
D
n + 2
… D
n - 3
… D
n - 5
Off
SERIAL-OUT
D
n - 8
D
n - 7
D
n - 6
D
n - 5
D
n - 5
Note : 1.OUT0~7=on when Dn="H" ; OUT0~7=off when Dn="L".
2. In order to ensure that the level of the power supply voltage is correct, an external resistor
must be connected betwen R-EXT and GND.
EQUIVALENT CIRCUIT OF INPUTS AND OUTPUTS
1. ENABLE terminal
V
DD
R
IN
(Up)
2. LATCH terminal
V
DD
ENABLE
LATCH
R
IN
(Down)
GND
GND
3. CLOCK, SERIAL-IN terminal
V
DD
CLOCK,
SERIAL-IN
GND
4. SERIAL-OUT terminal
V
DD
SERIAL-OUT
GND
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V.2.10
SAMHOP [ SAMHOP MICROELECTRONICS CORP. ]
