TLC59291_16 Datasheet, PDF (37/46 Pages) Texas Instruments – 8/16-Channel, Constant Current LED Driver

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9 Application and Implementation
TLC59291
SLVSA96A – SEPTEMBER 2015 – REVISED MARCH 2016
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application Information
The device is a 8/16-channel, constant sink current, LED driver. This device is typically connected in series to
drive many LED lamps with only a few controller ports. On/Off control data and FC control data can be written
from the SIN input terminal. The device has six type error flags: LED open detection (LOD), LED short detection
(LSD), output leak detection (OLD), reference terminal short detection (ISF), Pre themal warning (PTW) and
thermal error flag (TEF).
9.2 Typical Application
In this application, the device VCC and LED lamp anode voltages are supplied from different power supplies.
V_LED
Controller
DATA
SCLK
LAT
BLANK
SID read
R_IREF
OUT0 - - - - - - - - - - OUT15
SIN
SOUT
SCLK
LAT
BLANK
IREF
TLC59291
IC1
VCC
GND
GND
3
V_CC
GND
R_IREF
OUT0 - - - - - - - - - - OUT15
SIN
SOUT
SCLK
LAT
BLANK
IREF
TLC59291
ICn
VCC
GND
GND
V_CC
GND
Figure 36. Multiple Daisy-chained TLC59291 Devices
9.2.1 Design Requirements
The parameters for the design example are shown in Table 16.
Table 16. Design Parameters
PARAMETER
VCC input voltage range
LED lamp (V_LED) input voltage range
SIN, SCLK, LAT, and GSCLK voltage range
VALUE
3 V to 5.5 V
Maximum LED forward voltage (V_F) + 0.3 V (knee voltage)
Low level = GND, High level = V_CC
9.2.2 Detailed Design Procedure
To begin the design process, a few parameters must be decided upon. The designer needs to know the
following:
• Maximum output constant-current value for each color LED lamp.
• Maximum LED forward voltage (V_F).
• Which error flags are used.
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