LT3593 Datasheet, PDF (1/16 Pages) Linear Technology – 1MHz White LED Driver with Output Disconnect and One Pin Current Programming

LT3593
1MHz White LED Driver with
Output Disconnect and One
Pin Current Programming
FEATURES
n _{Drives Up to Ten White LEDs from a 3V Supply}
n _{One Pin Shutdown and Current Programming}
n _{LEDs Disconnected in Shutdown}
n _{32:1 Linear Brightness Control Range}
n _{VIN Range: 2.7V to 5.5V}
n _{±5% Output Current Accuracy at Full Scale}
n _{Low Shutdown Current: 3μA}
n _{1MHz Switching Frequency}
n _{Requires Only 1μF Output Capacitor}
n _{Low Profile 6-Lead DFN (2mm × 2mm × 0.75mm)}
and 6-Lead SOT-23 Packages
APPLICATIONS
n _{Cell Phones}
n _{Digital Cameras}
n _{PDAs, Handheld Computers}
n _{MP3 Players}
n _{GPS Receivers}
DESCRIPTION
The LT^®3593 is a step-up DC/DC converter designed to
drive up to ten white LEDs in series from a Li-Ion cell.
Series connection of the LEDs provides identical LED
currents and eliminates the need for ballast resistors. The
device features a unique high side LED current sense that
enables the part to function as a “one wire current source”
where the low side of the LED string can be returned to
ground anywhere.
Additional features include output disconnect in shutdown,
open LED protection and 1-pin shutdown/LED current
control. The CTRL pin is toggled to adjust the LED current
via an internal counter and a 5-bit DAC.
The LT3593 switches at 1MHz, allowing the use of tiny
external components. Constant frequency switching re-
sults in low input noise and a small output capacitor. The
LT3593 is available in the 6-lead DFN (2mm × 2mm) as
well as the 6-lead SOT-23 packages.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
Li-Ion Driver for Ten White LEDs
10μH
V_IN
3V TO 5V
1μF
1μF
V_IN
SW
CAP
SHUTDOWN AND
CURRENT CONTROL
LT3593
CTRL
LED
GND
3593 TA01a
Conversion Efficiency
90
V_IN = 3.6V
10 LEDs
80
70
60
50
40
30
0
5
10
15
LED CURRENT (mA)
20
3593 TA01b
3593f
1