2
dc1573af
DEMO MANUAL DC1573A
qUick stArt proceDUre
Figure 1. Proper Measurement Setup Drawing
Demonstration circuit 1573A is easy to set up to evaluate
the performance of the LT3760. Follow the procedure below:
Note: PWM must be pulled high to work. If PWM is not
used, tie PWM high or connect to REF on the PCB using
resistor R9.
1. Connect strings of LEDs with forward voltage less than
45V, but greater than the PV
IN
voltage, to the LED+ and
LED1-8 terminals on the PCB as shown in Figure 1. Tie
any unused LED1-8 pins directly to V
OUT
(LED+) before
power-up to disable that channel.
2. Connect the
SHDN
terminal to GND.
3. With power off, connect the PV
IN
power supply to the
PV
IN
and GND terminals within the range specified on
the PCB. Make sure that the PV
IN
DC input voltage does
not exceed the forward voltage of the LED string.
4. With power off, connect the V
IN
power supply to the
V
IN
and GND terminals within the range specified on
the PCB.
5. Connect the PWM terminal. If PWM is not used, tie PWM
high or connect to REF on the PCB using resistor R9.
PWM must be pulled high to work.
6. Turn the PV
IN
power supply on.
7. Turn the V
IN
power supply on after PV
IN
.
8. Release the
SHDN
-to-GND connection.
9. Observe the LED strings running at the programmed
LED current.
Note: For PWM dimming, connect a PWM (100Hz or higher)
signal to the PWM terminal and observe the reduction of
brightness in the LED string when PWM dimming.