DC1166A - Demo Manual

DEMO CIRCUIT 1166
LT3590
QUICK START GUIDE
LT3590
48V Buck-Mode LED Driver
DESCRIPTION
WARNING!
Do not look directly at operating LED.
This circuit produces light that can damage eyes.
Demonstration circuit 1166 is a 48V Buck-Mode
LED Driver featuring the LT3590. The LT3590 is a
fixed frequency buck mode converter specifically
designed to drive up to 10 LEDs in series from a
48V DC source. Series connection of the LEDs
provides identical LED currents of up to 50mA, resulting in uniform brightness and eliminating the
need for ballast resistors. A fixed frequency current
mode architecture results in stable operation over
a wide range of input voltage and load condition.
The high switching frequency allows using tiny
components for the circuit.
The LT3590 datasheet gives complete descriptions
of the part, operation and application information.
The datasheet must be read in conjunction with
this quick start guide for working on or modifying
the demo circuit 1166.
Design files for this circuit board are available.
Call the LTC factory.
L, LTC, LTM, LT are trademarks of Linear Technology Corporation. Other product
names may be trademarks of the companies that manufacture the products.
PERFORMANCE SUMMARY Specifications are at TA = 25°C
SYMBOL
VIN
DMAX
IQSHDN
FSW
VREG
Eff
PARAMETER
Input Supply Range
Maximum Duty Cycle
Quiescent Current in Shutdown
Switching Frequency
VREG Pin Voltage
Efficiency
CONDITIONS
MIN
4.5
90
VIN = 48V
1mA load on VREG pin
VIN = 48V; VLED = 30V; ILED = 50mA
650
3.1
TYP
MAX
55
15
850
3.3
90
20
1050
3.5
UNITS
V
%
µA
KHz
V
%
QUICK START PROCEDURE
Demonstration circuit 1166 is easy to set up to
evaluate the performance of the LT3590. Refer to
Figure 1 for proper measurement equipment setup
and follow the procedure below:
1. Place jumpers in the following positions:
JP1 ON
3. With power off, connect LEDs to LED+ and
LED-.
4. Turn on the power at the input.
NOTE. Make sure that the input voltage does not exceed 55V.
5. Check for the proper output voltage and current.
2. With power off, connect the input power supply
to VIN and GND.
1
LT3590
Figure 1. Proper Measurement Equipment Setup
2
LT3590
3
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