FEATURES
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LT3590
48V Buck Mode
LED Driver in SC70
and 2mm x 2mm DFN
DESCRIPTION
The LT
®
3590 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
output voltage.
The high switching frequency of 850kHz permits the use
of tiny, low profile inductors and capacitors. A single pin
performs both shutdown and accurate LED dimming
control. The power switch, Schottky diode and control
circuitry are all contained inside a space saving SC70
package or 2mm × 2mm DFN package to allow a small
converter footprint and lower parts cost.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
4.5V to 55V Input Voltage Range
Up to 50mA LED Current
80mA, 55V Switch
Internal Schottky Diode
15μA Supply Current in Shutdown
500μA Supply Current Operating, Not Switching
Switching Frequency: 850kHz
200mV Feedback Voltage with ±5% Accuracy
CTRL Input Performs Dimming and Shutdown
91% Efficiency (10 LEDs, 50mA)
Requires Only 1μF Output Capacitor
8-Lead SC70 Package
6-Lead 2mm × 2mm DFN Package
APPLICATIONS
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LED Fixed Signage
Traffic Signs
Neon Sign Replacement
TYPICAL APPLICATION
Buck Mode Driver for Ten White LEDs
1μF
50mA
4Ω
V
IN
48V
1μF
CONTROL
V
IN
CTRL
LT3590
VREG
0.1μF
GND
SW
50
3590 TA01a
Conversion Efficiency
100
90
EFFICIENCY (%)
80
70
60
LED
470μH
40
0
10
20
30
LED CURRENT (mA)
40
50
3590 TA01b
3590f
1
LINER [ LINEAR TECHNOLOGY ]
