Texas Instruments TLC5929, Руководство пользователя

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Test Set Up
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5 Test Set Up
5.1 Equipment
5.1.1 Voltage Source
V
CC
supply (TLC5929 Driver): 3–5.5 V at 50 mA.
V
LED
supply: 5 V at more than 16 times the set output current, I
REF
CAUTION
Do not operate without LED loads. The TLC5929 outputs are bipolar and can
draw high I
CC
current when no load is connected. In addition the fault protection
will be triggered.
Connect V
CC
to J6 and V
LED
to J5 as shown in Figure 2 .
5.1.2 Serial Interface
Evaluate this EVM by preparing a signal pattern generator like an FPGA, CPLD, MCU or some equipment
like DG2020 for the input signals. Connector J1 or TP1 to TP4 connect the signals BLANK (pin 7 or TP4),
SIN (pin 10 or TP3), SCLK (pin 9 or TP2), LAT (pin 8 or TP1), and GND (pin 6 or TP10).
5.2 Equipment Setup
Figure 2 shows the basic test set up recommended to evaluate the TLC5929 EVM. Note that although the
return for J5 and J6 are the same system ground, the connections should remain separate as shown in
Figure 2 .
5.2.1 Procedure
1. Working at an ESD workstation, make sure that any wrist straps, bootstraps, or mats are connected
referencing the user to earth ground before power is applied to the EVM. Wear electrostatic smock and
safety glasses.
2. Before connecting the DC input sources, V
CC
and V
LED
, limit the source currents. Set V
CC
and V
LED
to
0 V, initially, and connect as shown in Figure 2 .
3. Place a jumper on J7 to the desired forward current. R5 personalizes the needed current, according to
Equation 1 in Section 4.2 .
4. Connect the DC power supplies, V
CC
and V
LED
, to the EVM as shown in Figure 2 .
5. Connect the pattern generator or MCU to the EVM as shown in Figure 2 .
6. Make sure the pattern generator or MCU is loaded with the EVM control software and the I/O levels
are compatible with the TLC5929 V
CC
supply. Example: if V
CC
= 3.3 V, then interface 3.3-V I/O’s to the
EVM board.
7. Using the timing diagram (Figure 9, TLC5929 ( SBVS159 ) datasheet) as a guide, load the TLC5929
registers and control the outputs as desired.
6 Using the TLC5929, 16-Channel LED Driver with 7-Bit Global Brightness SLVU756 – August 2012
Control, Power-Save Mode, and Full Self-Diagnosis for LEDs
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