Full-Featured LED Driver
with 1.5A Switch Current
■ 5000:1 True Color PWMTM Dimming Ratio
■ 1.5A, 45V Internal Switch
■ 100mV High Side Current Sense
■ Open LED Protection
■ Adjustable Frequency: 250kHz to 2.5MHz
■ Wide Input Voltage Range:
Operation from 3V to 30V
Transient Protection to 40V
■ Operates in Boost, Buck Mode and Buck-Boost Mode
■ Gate Driver for PMOS LED Disconnect*
■ Constant-Current and Constant-Voltage Regulation
■ CTRL Pin Provides 10:1 Analog Dimming
■ Low Shutdown Current: <1μA
■ Available in (4mm × 4mm) 16-Lead QFN and 16-Pin
■ Display Backlighting
■ Automotive and Avionic Lighting
The LT®3517 is a current mode DC/DC converter with an
internal 1.5A, 45V switch speciﬁcally designed to drive
LEDs. The LT3517 operates as a LED driver in boost,
buck mode and buck-boost mode. It combines a tradi-
tional voltage loop and a unique current loop to operate
as a constant-current source or constant-voltage source.
Programmable switching frequency allows optimization of
the external components for efﬁciency or component size.
The switching frequency of LT3517 can be synchronized
to an external clock signal. The LED current is externally
programmable with a 100mV sense resistor. The external
PWM input provides up to 5000:1 LED dimming. The CTRL
pin provides further 10:1 dimming ratio.
The LT3517 is available in the tiny footprint 16-Lead QFN
(4mm × 4mm) and the16-Pin TSSOP packages. The LT3517
provides a complete solution for both constant-voltage
and constant-current applications.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
True Color PWM is a trademark of Linear Technology Corporation. Patent Pending.
All other trademarks are the property of their respective owners.
1A Buck Mode LED Driver
TGEN VREF VC GND
CTRL = VREF
20 40 60 80
PWM DUTY CYCLE (%)