TLC5910 Datasheet, PDF (14/30 Pages) Texas Instruments – LED DRIVER

TLC5910
LED DRIVER
SLLS392 – NOVEMBER 1999
PRINCIPLES OF OPERATION
Latch for Gray Scale Data
XLATCH
OUT15
Data
(10 bits)
OUT14
Data
(10 bits)
OUT1
Data
(10 bits)
OUT0
Data
(10 bits)
DOUT0 to 9
Shift Register for Gray Scale Data
16th byte
DIN9 MSB
DIN0 LSB
15th byte
DIN9 MSB
DIN0 LSB
2nd byte
DIN9 MSB
DIN0 LSB
1st byte
DIN9 MSB
DIN0 LSB
DCLK
DIN0 to 9
Figure 3. Relationship Between Shift Register and Latch for Gray Scale Data
shift register latch for brightness control
The shift register latch for brightness control is configured with 1 × 10 bits. Using the shift register latch for
brightness control, the division ratio of the gray scale clock can be set and the output current value on constant
current output can be adjusted. When powered up, the latch data is indeterminate and the shift register is not
initialized. Data should be written to the shift register latch prior to lighting-on (BLANK=L) when these functions
are used. Also, the latch value for brightness control cannot be rewritten when the constant current output is
turned on. When these functions are not used, the latch value can be set to the default value setting BCENA
to low level (connect to GND). Also, DIN9 is assigned to the LSB of the reference current control to maintain
the compatibility with TLC5901/02/03 family. The configuration of the shift register and the latch for brightness
control is shown below.
Latch for Brightness Control
XLATCH
Gray Scale Clock Division Ratio Data Set Current Data Adjusted On Constant Current Output
0
0
MSB
0
0
1
1
1
LSB MSB
1
1
1
LSB
(Note A)
DOUT0 to 9
Shift Register for Brightness Control
DIN8
DATA
DIN7
DATA
DIN6
DATA
DIN5
DATA
DIN4 DIN3
DATA DATA
DIN2
DATA
DIN1
DATA
DIN0
DATA
DIN9
DATA
DCLK
DIN0 to 9
Note A: Indicates default value at BCENA low.
Figure 4. Relationship Between Shift Register and Latch for Brightness Control
shift register latch for dot correction
The shift register latch for dot correction is configured with 16 × 6 bits. Using the shift register latch for dot
correction, the current value on the constant current output can be set individually. When powered up, the latch
data is indeterminate and the shift register is not initialized. Data should be written to the shift register latch prior
to lighting-on (BLANK=L) when these functions are used. Also, the latch value for dot correction cannot be
rewritten when the constant current output is turned on. When these functions are not used, the latch value can
be set to the default value setting of DCENA to low level (connect to GND). The configuration of the shift register
and the latch for dot correction is shown in Figure 5.
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