Datasheet LT3597 (Analog Devices)

LT3597 60V Triple Step-Down LED Driver
FeaTures DescripTion
n
Three 100mA Buck Regulators, Each Drives Up to
The LT®3597 is a 60V triple step-down LED driver capable
10 LEDs with Fast NPN Current Sources
of achieving 10,000:1 digital PWM dimming at 100Hz with n
Fast Current Sources for <1µs Pulse Widths
fast NPN current sources driving up to 10 LEDs in each
(10,000:1 True Color PWM™ Dimming at 100Hz)
channel. LED dimming can also be achieved via analog n
LEDs Disconnected in Shutdown
control of the CTRL1-3 pin. n
Adaptive VOUT for Increased Efficiency
The step-down switching frequency is programmed be- n
6V to 60V Input Voltage Range
tween 200kHz and 1MHz. The frequency is also synchroniz- n ±2% LED Current Matching able to an external clock. The LT3597 provides maximum n External Resistor Sets LED Current for Each Channel LED brightness while adhering to manufacturers’ speci- n Internal Compensation and Soft-Start fications for thermal derating. The derate temperature is n Programmable Switching Frequency (200kHz to 1MHz) programmed by placing a negative temperature coefficient n Synchronizable to External Clock (NTC) resistor on the master control pin. n Open LED Detection and Reporting n Shorted LED Pin Protection and Reporting The LT3597 adaptively controls VOUT in order to achieve n Programmable LED Thermal Derating optimal efficiency. Other features include: 2% LED cur- n Programmable Temperature Protection rent matching between channels, open LED reporting, n 5mm × 8mm Thermally Enhanced QFN Package shorted LED protection, programmable LED current, and with a 0.6mm High Voltage Pin Spacing programmable temperature protection. L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. True Color
applicaTions
PWM is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n LED Billboards and Signboards n Mono, Multi, Full-Color LED Displays n Large Screen Display LED Backlighting n Automotive, Industrial, and Medical Displays
Typical applicaTion Triple Step-Down RGB Single Pixel LED Driver, 100mA Current
VIN 48V VIN BOOST2 10µF 270k 0.1µF 100µH V
10,000:1 PWM Dimming at 100Hz
OUT2 EN/UVLO SW2 91k 3.3µF 97k BOOST1 DA2 VOUT1 100µH 0.1µF 9.1k G SW1 FB2 97k 3.3µF PWM DA1 VOUT2 2V/DIV R 9.1k LED2 FB1 LT3597 L BOOST3 0.1µF 100µH VOUT3 VOUT1 SW3 ILED LED1 3.3µF 97k 50mA/DIV VCC BIAS DA3 5V 10µF 100k 9.1k B FB3 3597 TA01b FAULT 200ns/DIV 3 PWM1-3 VOUT3 3 CTRL1-3 LED3 SYNC VREF VREF RT 10k 82.5k TSET 33.2k CTRLM ISET1 ISET2 ISET3 GND 49.9k 3597 TA01a 100k (1MHz) 20k 20k 20k 3597fa 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts