R
(k ) =
W
IREF
V
(V)
IREF
I
(mA)
OLC
´
41.9
Connector and Test Point Descriptions
4.2
I
REF
Jumpers (J7)
The 2 × 5 header, J7, selects the desired maximum output current. The currents available for the
TLC59282 are 10, 20, 30, and 40 mA per channel.
For the TLC59282, R5 is not populated because the maximum forward current is 45 mA.
NOTE:
The LEDs connected to J3 do not turn on if there is no jumper set at J7.
(1)
Where:
V
IREF
= the internal reference voltage on the IREF pin (typically 1.205 V)
I
OLC
= 2 mA to 35 mA for V
CC
≤
3.6 V, or 2 mA to 45 mA for V
CC
> 3.6 V
4.3
Test Point Descriptions
Table 3. Test Point Description
Test Points
Name
Type
Description
TP1
LAT
Input
Level-triggered latch. The data is held when LAT is low. The data is transferred to the on/off
data latch when LAT is high.
TP2
SCLK
Input
Serial data shift clock input
TP3
SIN
Input
Serial data input for the shift register
TP4
BLANK Input
Output enable for all channels. Outputs are disabled when BLANK is high.
TP5
VCC
Power
Supply for TLC59282 (3–5.5 V).
TP6
SOUT
Output
Serial data output
TP7
I
REF
I/O
Constant-current set resistor
TP8
V
LED
Power
Power supply for LED lamps (up to 17 V)
TP9, TP10
GND
Power
Power ground
4.3.1
Input Voltage Monitoring (TP5, TP8, TP9, TP10)
The TLC59282 EVM provides test points for measuring the voltage applied to the IC and the LEDs. This
allows measurement of the actual supply voltages without losses from input cables and connectors.
The V
CC
voltage measurements are made between TP5 and TP10. The V
LED
voltage measurements are
made between TP8 and TP9. Use these test points by connecting a voltmeter positive terminal to TP5/8
and negative terminal to TP9/10.
4.3.2
Serial Interface Connection (TP1, TP2, TP3, TP4, TP6)
Evaluate this EVM by preparing a signal pattern generator like an FPGA, CPLD, MCU or some equipment
like DG2020 for the input signals BLANK (TP4), SIN (TP3), SCLK (TP2) and LAT (TP1).
Use TP6 for observing the signal SOUT sends to a second EVM (not included).
4.3.3
Constant Sink Current (TP7)
Measure the voltage present at the I
REF
pin of the TLC59282 with TP7.
5
SLVU672 – August 2012
Using the TLC59282, 16-Channel LED Driver
Copyright © 2012, Texas Instruments Incorporated