Datasheet LT3496 (Analog Devices)

LT3496 Triple Output LED Driver Features Description n
True Color PWM™ Dimming Delivers Up to 3000:1
The LT®3496 is a triple output DC/DC converter designed
Dimming Ratio
to operate as a constant-current source and is ideal for n
Built-In Gate Driver for PMOS LED Disconnect
driving LEDs. The LT3496 works in buck, boost or buck- n
Three Independent Driver Channels with 750mA,
boost mode. The LT3496 uses a fixed frequency, current
45V Internal Switches
mode architecture resulting in stable operation over a n
Operates in Buck, Boost, Buck-Boost Modes
wide range of supply and output voltages. A frequency n CTRL Pin Accurately Sets LED Current Sense adjust pin allows the user to program switching frequency Threshold Over a Range of 10mV to 100mV between 330kHz and 2.1MHz to optimize efficiency and n Adjustable Frequency: 330kHz to 2.1MHz external component size. n Open LED Protection The LT3496 supports 3000:1 dimming control on each n Wide VIN Supply Range: channel. Each of the three regulators is independently Operation from 3V to 30V operated by that channel’s PWM signal. The PWM feature Transient Protection to 40V allows precise adjustment of the color mixing or dimming n Surface Mount Components ratio of the LED source. Each of the three channels has n 28-Lead (4mm × 5mm) QFN and TSSOP Packages a built-in gate driver to drive an external LED-disconnect applications P-channel MOSFET, allowing high dimming range. The output current range of each channel of the LT3496 is n programmed with an external sense resistor. RGB Lighting n Billboards and Large Displays The CTRL pins are used to adjust the LED currents either n Automotive and Avionic Lighting for analog dimming or overtemperature protection. n Constant-Current Sources L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT and True Color PWM are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 7199560, 7321203, and others pending. typical application
High Dimming Ratio Triple Output LED Power Supply
PVIN 42V CAP1 CAP2 CAP3 1µF s3 200mΩ 200mΩ 200mΩ
3000:1 PWM Dimming at 120Hz
LED1 LED2 LED3 TG1 TG2 TG3 PWM 5V/DIV 7 LEDs 0.5A 0.5A 0.5A IL 0.5A/DIV I 0.47µF 0.47µF 0.47µF LED 18µH 18µH 18µH 0.5A/DIV 0.5µs/DIV 3496 TA01b SW1 SW2 SW3 TG1, TG2, TG3 CAP1, CAP2, CAP3 VC1, VC2, VC3 LED1, LED2, LED3 V LT3496 VREF 22k IN VIN CTRL1, CTRL2, CTRL3 3V TO 24V PWM1, PWM2, PWM3 PWM1, PWM2, PWM3 fADJ 470pF 1µF SHDN SHDN GND OVP1, OVP2, OVP3 3496 TA01a 3496ff Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Typical Applications Package Description Revision History Typical Application Related Parts