LT3952 is a new current mode boost DC-DC converter from Linear Technology. It has an internal 60V, 4A DMOS power switch. It is a highly compact solution specifically designed to drive high-power LEDs in multiple configurations.
The device combines input and output current regulation loops with output voltage regulation for use as a flexible current / voltage source. The LT3952's 3V to 42V input voltage range makes it ideal for a variety of applications, including automotive, industrial, and architectural lighting.
The LT3952 can drive up to 16 350mA white LEDs with a nominal 12V input and its output power exceeds 15W. It has a high-side current detection function that can be used in boost mode, buck mode, buck-boost mode or SEPIC topology. Internal spread-spectrum frequency modulation minimizes EMI issues. The LT3952 provides over 94% efficiency in a boost topology, eliminating the need for external heat sinks, and internal LED short-circuit protection makes most applications require higher reliability. The frequency adjustment pin allows the user to program the switching frequency from 200kHz to 3MHz, thereby optimizing efficiency while reducing external component size and cost. The LT3952 provides more than 90% efficiency, while switching at 2MHz with a small solution footprint.
The LT3952 has a gate driver for PMOS LED isolation switches, which can provide up to 4,000: 1 dimming ratio using an external PWM signal. For less stringent dimming requirements, the CTRL pin can be used to provide a 10: 1 analog dimming range, while the internal PWM generator can be used for 5: 1 dimming. The LT3952's fixed frequency, current mode architecture provides stable operation over a wide range of power and output voltage ranges. Output short circuit protection and open LED protection improve system reliability. Other features include frequency synchronization, spread-spectrum frequency modulation, programmable VIN undervoltage and overvoltage protection, and input current limit and monitor.
The LT3952EFE is available in a thermally enhanced 28-lead TSSOP package. Three temperature grades are available, with extended and industrial grade operating temperatures ranging from -40C to 125C (junction), and high-temperature grades from -40C to 150C.
