TLC5949 Datasheet, PDF (29/51 Pages) Texas Instruments – 16-Channel, 12-Bit, ES-PWM, Full Self-Diagnosis LED Driver for 7-Bit Global BC LED Lamp

TLC5949
www.ti.com
SBVS219A – DECEMBER 2012 – REVISED DECEMBER 2012
First and Second Control Data Latch
The first and second control data latches are 137 bits and 119 bits long, respectively. The first latch contains
global brightness control (BC) data and function control (FC) data; the second latch contains global BC data. The
DC for each constant-current output and the BC for all constant-current outputs are controlled by the second
control data latch. The control data in the first latch are set by the least significant 137 bits from the common shift
register at the LAT rising edge when the common shift register MSB is '1'. The 119 bits of BC data from the first
control data latch are copied to the second latch when the 4096th GSCLK occurs or when the BLANK bit in the
first control data latch is set to '1'.
When the device is powered up, the data in the first latch (except the BLANK and PSMODE bits of the FC bits)
and second latch are random. Therefore, BC and FC data must be written to the first and second control data
latches before turning on the constant-current outputs. The default value of the BLANK bit is '1'. The first and
second control data latch configurations are shown in Figure 29.
From Common Shift Register
First Control Data Latch (137 Bits)
Lower 137 Bits
MSB
136-119 118-112 111-105 104-98
FC
Bits
17-0
BC
Bits[6:0]
for OUTn
(1)
RSV
Bits
RSV
Bits
FC,
BC,
18 Bits 7 Bits
97-91 90-84
RSV
Bits
RSV
Bits
27-21 20-14
RSV
Bits
RSV
Bits
112 Reserved Bits (Write ‘1’ to All Bits)
13-7
RSV
Bits
Second Control Data Latch (119 Bits)
119 Bits
MSB
118-112 111-105 104-98
BC
Bits[6:0]
for OUTn
RSV
Bits
RSV
Bits
BC,
7 Bits
97-91 90-84
RSV
Bits
RSV
Bits
27-21 20-14
RSV
Bits
RSV
Bits
112 Reserved Bits (Write '1' to All Bits)
18 Bits
7 Bits
112 Bits
LSB
6-0
RSV
Bits
13-7
RSV
Bits
This latch pulse comes
from the LAT pin when
the MSB of the Common
Shift Register is ‘1’.
LSB
6-0
The 4096th GSCLK is used
to latch the data when the
RSV
Auto Display Repeat is
Bits
enabled or when the BLANK bit
is set to ‘1’.
To
To
Function Global Brightness
Control Circuit Control Circuit
(1) RSV = reserved.
No
Applied
Bits
Figure 29. First and Second Control Data (BC and FC) Latch Configuration
Global Brightness Control (BC) Data
Global BC data are seven bits long. The global brightness for all outputs is controlled by the second control data
latch. The data are used to adjust the constant-current values for the 16 constant-current outputs. As explained
in the Global Brightness Control (BC) Function section, the BC values are used to adjust the output current from
25% to 100% of the maximum value. The global BC data bit assignment in the first and second latches is shown
in Table 6. Table 2 summarizes the BC data value versus set current value.
Table 6. Global Brightness Control Data Bit Assignment in the Control Data Latch
BIT NUMBER
118-112
BIT NAME
BC
CONTROLLED CHANNEL
BC[6:0] bits for all channels (OUT0-OUT15)
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