n 3000:1 True Color PWMTM Dimming
n Wide Input Voltage Range: 6V to 100V
n Output Voltage Up to 100V
n Constant-Current and Constant-Voltage Regulation
n 100mV High Side Current Sense
n Drives LEDs in Boost, Buck Mode, Buck-Boost Mode,
SEPIC or Flyback Topology
n Adjustable Frequency: 100kHz to 1MHz
n Open LED Protection
n Programmable Undervoltage Lockout with Hysteresis
n Open LED Status Pin (LT3756)
n Frequency Synchronization (LT3756-1)
n PWM Disconnect Switch Driver
n CTRL Pin Provides Analog Dimming
n Low Shutdown Current: <1μA
n Programmable Soft-Start
n Thermally Enhanced 16-Lead QFN (3mm × 3mm)
and MSOP Packages
n High Power LED Applications
The LT®3756 and LT3756-1 are DC/DC controllers designed
to operate as a constant-current source for driving high
current LEDs. They drive a low side external N-channel
power MOSFET from an internal regulated 7V supply. The
ﬁxed frequency, current-mode architecture results in stable
operation over a wide range of supply and output voltages.
A ground referenced voltage FB pin serves as the input for
several LED protection features, and also makes it possible
for the converter to operate as a constant-voltage source.
A frequency adjust pin allows the user to program the
frequency from 100kHz to 1MHz to optimize efﬁciency,
performance or external component size.
The LT3756/LT3756-1 sense output current at the high
side of the LED string. High side current sensing is the
most ﬂexible scheme for driving LEDs, allowing boost,
buck mode or buck-boost mode conﬁguration. The PWM
input provides LED dimming ratios of up to 3000:1, and the
CTRL input provides additional analog dimming capability.
Both parts are available in the 16-lead QFN (3mm × 3mm)
and MSOP packages.
LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are
the property of their respective owners. Protected by U.S. Patents, including 7199560
8V TO 60V
94% Efﬁcient 30W White LED Headlamp Driver
Efﬁciency vs VIN
20 40 60