LT3743 Datasheet | Linear Technology

Features High Current Synchronous Step-Down LED Driver with Three-State Control DESCRIPTION nn PWM Dimming Provides Up to 3000:1 Dimming Ratio nn CTRL_SEL Dimming Provides Up to 3000:1 Dimming Ratio Between Any Current nn Three-State Current Control for Color Mixing nn ±6% Current Regulation Accuracy nn 6V to 36V Input Voltage Range nn Average Current Mode Control nn 2µs Maximum Recovery Time Between Any Current Regulation State nn <1µA Shutdown Current nn Output Voltage Regulation and Open-LED Protection nn Thermally Enhanced 4mm × 5mm QFN and 28-Pin FE Package APPLICATIONS nn DLP Projectors nn High Power Architectural Lighting nn Laser Diodes The LT®3743 is a fixed frequency synchronous step-down DC/DC controller designed to drive high current LEDs. The average current mode controller will maintain inductor current regulation over a wide output voltage range of 0V to (VIN - 2V). LED dimming is achieved through analog dimming on the CTRL_L, CTRL_H and CTRL_T pins and with PWM dimming on the PWM and CTRL_SEL pins. Through the use of externally switched load capacitors, the LT3743 is capable of changing regulated LED current levels within several µs, providing accurate, high speed PWM dimming between two current levels. The switching frequency is programmable from 200k Hz to 1MHz through an external resistor on the RT pin. Additional Features include voltage regulation and overvoltage protection set with a voltage divider from the output to the FB pin. Overcurrent protection is provided and set by the CTRL_H pin. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and 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, 7321203, 8120335 and 8901904. TYPICAL APPLICATION 92% Efficient 20A LED Driver EN/UVLO PWM CTRL_SEL 82.5k 2.2n F 100k RHOT 499Ω 100k RNTC 10k 10n F EN/UVLO PWM CTRL_SEL RT SYNC VIN...