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SBVS140 – MARCH 2010
3-Channel, 12-Bit, PWM LED Driver with
Buck DC/DC Converter and Differential Signal Interface
Check for Samples:
1
FEATURES
3-Channel, Constant-Current Sink Output
Current Capability: 150 mA per channel
Grayscale (GS) Control with PWM:
12-bit (4096 steps)
Dot Correction (DC): 7-bit (128 steps)
Global Brightness Control (BC):
7-bit (128 steps)
EEPROM for Dot Correction Storage
Input Voltage: Up to 36 V
LED Supply Voltage: Up to 17 V with Auto LED
Anode Voltage Control
Constant-Current Accuracy:
– Channel-to-Channel = ±0.5% (typ)
– Device-to-Device = ±3% (typ)
Data Transfer Rate: 20 MHz
Differential Signal Interface for Long Distance
Cascading
Unlimited Device Cascading
Auto Display Repeat/Auto Data Refresh
Internal/External Selectable GS Clock
Thermal Shutdown (TSD)
Packages: HTSSOP-32 and QFN-28
VCC
Power
Supply
GND
APPLICATIONS
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Full-Color Static LED Displays for Building
Wall
Long Distance and Large Area Illumination
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DESCRIPTION
The TLC5970 is a three-channel, constant-current
sink driver with a buck dc/dc converter and a
differential signal interface. Each channel has
individually adjustable currents with 4096 PWM
grayscale (GS) steps and 128 constant-current sink
steps for dot correction (DC). The dot correction
adjusts the brightness variations between LEDs. The
DC data can be stored in the internal EEPROM. Also,
current through all three channels can be controlled
by global brightness control (BC) data with 128 steps.
GS control, DC, and BC are accessible via a
differential signal interface. The maximum current
value for each channel is set by a single external
resistor. The TLC5970 contains a dc/dc buck
converter. The dc/dc converter improves system
efficiency, reduces system level currents, and allows
thinner gauge wiring by optimizing the LED anode
voltage to keep the LED cathode voltage to 1 V. The
TLC5970 proivdes overtemperature protection by
turning all output drivers off when the IC temperature
is too high (exceeds +138°C).
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GND
SWOFF
0.01
m
F
0.1
m
F
VREG
VREGIF
IREF2
IREF1
IREF0
Controller
SDTY
SDTZ
SDKY
SDKZ
Open
VROM
SDTA
SDTB
SCKA
SCKB
VCC
PH
BOOT
FB
0.01
m
F
0.01
m
F
0.1
m
F
GND
SWOFF
VREG
VREGIF
IREF2
VCC
PH
BOOT
FB
0.01
m
F
OUT2
OUT1
OUT0
SDTY
SDTZ
SCKY
SCKZ
Open
IREF1
IREF0
VROM
SDTA
SDTB
SCKA
SCKB
OUT2
OUT1
OUT0
SDTY
SDTZ
SCKY
SCKZ
TLC5970
TLC5970
Typical Application Circuit Example
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3
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Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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Copyright © 2010, Texas Instruments Incorporated
UNLESS OTHERWISE NOTED this document contains
PRODUCTION DATA information current as of publication date.
Products conform to specifications per the terms of Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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