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TLC5943_17 Datasheet, PDF (19/40 Pages) Texas Instruments – 16-Channel, 16-Bit PWM LED Driver with 7-Bit Global Brightness Control
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TLC5943
www.ti.com
SBVS101 – DECEMBER 2007
When the IC powers on, the data in the Grayscale Shift Register and latch 1/2 are not set to any default value.
Therefore, grayscale data must be written to the Grayscale latch before turning on the constant current output.
Additionally, BLANK should be high when the device turns on, to prevent the outputs from turning on before the
proper grayscale and brightness control values can be written. All constant current outputs are always off when
BLANK is high. Equation 3 determines each output (OUTn) total on time (tOUTON):
tOUTON (ns) = TGSCLK (ns) ´ GSn
Where:
• TGSCLK = the period of GSCLK
• GSn = the programmed grayscale value for OUTn (GSn = 0 to 65,535d)
Table 4 summarizes the GS data versus OUTn on duty and on time.
GS DATA (Decimal)
0
1
2
3
---
8191
8192
8193
---
16381
16382
16383
16384
16385
16386
16387
---
24575
24576
24577
---
32765
32766
32767
Table 4. GS Data versus OUTn Total On Duty
GS DATA (Hex)
0
1
2
3
---
1FFF
2000
2001
---
3FFD
3FFE
3FFF
4000
4001
4002
4003
---
5FFF
6000
6001
7FFD
7FFE
7FFF
ON-TIME DUTY (%)
0
0.002
0.003
0.005
---
12.499
12.5
12.502
---
24.996
24.997
24.999
25
25.002
25.003
25.005
---
37.499
37.501
37.502
---
49.996
49.998
49.999
GS DATA (Decimal)
32768
32769
32770
32771
---
40959
40960
40961
---
49149
49150
49151
49152
49153
49154
49155
---
57343
57344
57345
---
65533
65534
65535
GS DATA (Hex)
8000
8001
8002
8003
---
9FFF
A000
A001
---
BFFD
C000
C001
C002
C003
C004
C005
---
DFFF
E000
E001
FFFD
FFFE
FFFF
(3)
ON-TIME DUTY (%)
50.001
50.002
50.004
50.005
---
62.499
62.501
62.502
---
74.997
74.998
75
75.001
75.003
75.004
75.006
---
87.5
87.501
87.503
---
99.997
99.998
100
Copyright © 2007, Texas Instruments Incorporated
Product Folder Link(s): TLC5943
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