LT3597_15 Datasheet, PDF (1/24 Pages) Linear Technology – 60V Triple Step-Down LED Driver

Features
n _{Three 100mA Buck Regulators, Each Drives Up to}
10 LEDs with Fast NPN Current Sources
n _{Fast Current Sources for <1µs Pulse Widths}
(10,000:1 True Color PWM™ Dimming at 100Hz)
n _{LEDs Disconnected in Shutdown}
n _{Adaptive VOUT for Increased Efficiency}
n _{6V to 60V Input Voltage Range}
n _{±2% LED Current Matching}
n _{External Resistor Sets LED Current for Each Channel}
n _{Internal Compensation and Soft-Start}
n _{Programmable Switching Frequency (200kHz to 1MHz)}
n _{Synchronizable to External Clock}
n _{Open LED Detection and Reporting}
n _{Shorted LED Pin Protection and Reporting}
n _{Programmable LED Thermal Derating}
n _{Programmable Temperature Protection}
n _{5mm × 8mm Thermally Enhanced QFN Package}
with a 0.6mm High Voltage Pin Spacing
Applications
n _{LED Billboards and Signboards}
n _{Mono, Multi, Full-Color LED Displays}
n _{Large Screen Display LED Backlighting}
n _{Automotive, Industrial, and Medical Displays}
LT3597
60V Triple Step-Down
LED Driver
Description
The LT^®3597 is a 60V triple step-down LED driver capable
of achieving 10,000:1 digital PWM dimming at 100Hz with
fast NPN current sources driving up to 10 LEDs in each
channel. LED dimming can also be achieved via analog
control of the CTRL1-3 pin.
The step-down switching frequency is programmed be-
tween 200kHz and 1MHz. The frequency is also synchroniz-
able to an external clock. The LT3597 provides maximum
LED brightness while adhering to manufacturers’ speci-
fications for thermal derating. The derate temperature is
programmed by placing a negative temperature coefficient
(NTC) resistor on the master control pin.
The LT3597 adaptively controls V_OUT in order to achieve
optimal efficiency. Other features include: 2% LED cur-
rent matching between channels, open LED reporting,
shorted LED protection, programmable LED current, and
programmable temperature protection.
L, 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.
Typical Application
Triple Step-Down RGB Single Pixel LED Driver, 100mA Current
V_IN
48V
10µF 270k
91k
V_OUT1
100µH
97k
3.3µF
R
9.1k
V_IN
EN/UVLO
BOOST1
0.1µF
SW1
DA1
FB1
LT3597
BOOST2
SW2
DA2
FB2
V_OUT2
LED2
BOOST3
V_OUT1
SW3
LED1
V_CC
BIAS
DA3
5V
10µF
100k
FB3
3
FAULT
3
PWM1-3
CTRL1-3
V_OUT3
LED3
SYNC
V_REF
RT
33.2k
I_SET1
I_SET2
I_SET3
T_SET
GND ^CTRLM
(1MHz)
20k
20k
20k
3597 TA01a
0.1µF 100µH
V_OUT2
3.3µF 97k
9.1k
0.1µF 100µH
V_OUT3
3.3µF 97k
9.1k
V_REF
10k
82.5k
49.9k
100k
10,000:1 PWM Dimming at 100Hz
G
PWM
2V/DIV
I_LED
50mA/DIV
B
200ns/DIV
3597 TA01b
3597fa
1