Performance Summary; Quick Start Procedure - Linear Technology DC2339A Demo Manual

DEMO MANUAL DC2339A
Description
LED CURRENT
Figure 1. DC2339A Current Rise Time. V

performance summary

SYMBOL PARAMETER
PV Input Supply Voltage
IN
V + Maximum Output Voltage
LED
I Output Current
OUT
f Switching Frequency
SW
EFF Efficiency at DC

Quick start proceDure

Demonstration circuit 2339A is easy to set up to evalu-
ate the performance of the LT3744. Refer to Figure 2 for
proper measurement equipment setup and follow the
procedure below:
1. With power off, connect the input power supply to PV
and GND. Note: make sure PV
nect a DC supply or a PWM signal to PWM1, PWM2
and/or PWM3.
2
PWM
2V/DIV
PWM
(YELLOW)
2V/DIV
(GREEN)
6.67A/DIV
= 12V, LED Voltage = 4.2V when ON. Total LED Current = 20A
IN
Specifications are at T
CONDITIONS
V + = 5V
LED
CTRL1, CTRL2, CTRL3 = 1.5V
V = 12V, I
IN
is below 36V. Con-
IN
2.00µs/DIV
= 25°C
A
= 20A, V = 5V
OUT OUT
2. With power off, connect the LED load to V
–
proper LED1 , LED2
of the PWM pins.
3. Turn on the power at the input. Turn on PWM1, PWM2
and/or PWM3.
IN
4. Carefully evaluate other design parameters as needed.
MIN TYP MAX
5.5 36
6.05
19 20 21
380 425 470
93.5
LED
– –
, LED3 according to the setting
UNITS
V
V
A
kHz
%
+ and
dc2339af