TLC59281 Datasheet, PDF (14/19 Pages) Texas Instruments – 16-Channel, Constant-Current LED Driver

TLC59281
SBVS139 – JANUARY 2010
www.ti.com
REGISTER CONFIGURATION
The TLC59281 has an on/off control data shift register and data latch. Both the on/off control shift register and
latch are 16 bits long and are used to turn the constant-current drivers on and off. Figure 17 shows the shift
register and latch configuration. The data at the SIN pin are shifted in to the LSB of the shift register at the rising
edge of the SCLK pin; SOUT data change at the rising edge of SCLK. The timing diagram for data writing is
shown in Figure 18. The driver on/off is controlled by the data in the on/off control data latch.
The on/off data are latched into the data latch by a rising edge of LAT after the data are written into the on/off
control shift register by SIN and SCLK. At the same time, the data in the on/off control shift register are replaced
with TI reserved data for production test. Therefore, LAT must be input only once after the on/off data update to
avoid the on/off control data latch being replaced with TI reserved data in the shift register. When the IC initially
powers on, the data in the on/off control shift register and latch are not set to the default values; on/off control
data must be written to the on/off control data latch before turning the constant-current output on. BLANK should
be high when the IC is powered on because the constant-current may be turned on at that time as a result of
random values in the on/off data latch. All constant-current outputs are forced off when BLANK is high.
On/Off Control Shift Register (1 Bit ´ 16 Channels)
MSB
15
14
13
12
11
On/Off Data On/Off Data On/Off Data On/Off Data
SOUT
for
for
for
for
¼
OUT15
OUT14
OUT13
OUT12
LSB
4
3
2
1
0
On/Off Data On/Off Data
for
for
OUT3
OUT2
On/Off Data On/Off Data
for
for
OUT1
OUT0
SIN
SCLK
¼
MSB
15
14
13
12
11
On/Off Data
for
OUT15
On/Off Data
for
OUT14
On/Off Data
for
OUT13
On/Off Data
for
OUT12
¼
LSB
4
3
2
1
0
On/Off Data On/Off Data
for
for
OUT3
OUT2
On/Off Data On/Off Data
for
for
OUT1
OUT0
LAT
On/Off Control Data Latch (1 Bit ´ 16 Channels)
16 Bits
To Constant Current Driver Control Block
Figure 17. On/Off Control Shift Register and Latch Configuration
14
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