TLC5943_17 Datasheet, PDF (21/40 Pages) Texas Instruments – 16-Channel, 16-Bit PWM LED Driver with 7-Bit Global Brightness Control

TLC5943
www.ti.com
SBVS101 – DECEMBER 2007
Auto Data Refresh Function
This function allows users to input Grayscale (GS) data or Brightness Control (BC) data any time without
synchronizing the input to the BLANK signal. If GS data or BC data are input during a display period, the input
data are held in the first latch for each data register. Data are then transferred to the second latch when the
65,536th GSCLK occurs. The second latch data are used for the next display period. Figure 25 through
Figure 27 show the timing.
However, when the high level signal of BLANK occurs before the 65,536th GSCLK, then the first latch data
upload to the second latch immediately. Also, when the XLAT rising edge inputs while BLANK is at a high level,
then the selected shift register data are transferred to the first and second latch at the same time. Bit 7 data of
BC update immediately whenever the data are written into the first latch.
SIN
GS0 GS0 GS0 GS0
4A 3A 2A 1B
GS0
0A
BC
BC BC BC BC BC BC
7A
6A 5A 4A 3A 2A 1A
BC
GS15 GS15 GS15 GS15
0A
15B 14B 13B 12B
SCLK
251 252 253 254 255 256
BCSEL
Low level ('L') = Grayscale Register is selected
1 2345678
High level ('H') = Brightness Register is selected
1234
XLAT
GSCLK
BLANK
Low level ('L')
65,536
65,535
12 3 4 5 6 7 8
GS Shift Register
(Internal)
Latest Grayscale Data
GSData
1st Latch (Internal)
Previous Grayscale Data
Latest Grayscale Data
GSData
2nd Latch (Internal)
Previous Grayscale Data
BC Shift Register
(Internal)
Previous Brightness Data
BCData
1st Latch (Internal)
Previous Brightness Data
BCData
2nd Latch (Internal)
Previous Brightness Data (Bit 0-Bit 6)
OFF
OUTn
ON
PWM/Brightness Controlled by Previous Data
SOUT
GS0 GS0 GS0 GS0 GS0
4
3
2
1
0
GS15
15A
BC BC BC BC BC BC BC BC
7
6
5
4
3
2
1
0
BC
7A
If there is no BLANK input when Auto Repeat is enabled.
Figure 25. Auto Refresh Data Function Timing 1
Latest Grayscale Data
Latest Brightness Data
Latest Brightness Data
Latest Brightness Data (Bit 0-Bit 6)
PWM/Brightness Controlled by Latest Data
GS15 GS15 GS15 GS15 GS15
15A 14A 13A 12A 11A
Copyright © 2007, Texas Instruments Incorporated
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