60VLED driver with internal 4A switch and PWM generator

     Linear Technology Corporation introduces the LT3952, a current mode boost DC/DC converter. The device has an internal 60V, 4A DMOS power switch. The LT3952 is specifically designed to drive high-power leds in multiple configurations. The device integrates input and output current regulation loops and output voltage regulation to operate 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, providing more than 15W of power. The device includes high voltage side current detection, allowing it to operate in boost mode, buck mode, buck-boost mode, or SEPIC topology. The internal spread spectrum frequency modulation minimizes EMI problems. The LT3952 provides over 94% efficiency in booster topology, so no external heat dissipation measures are required. Its internal LED short-circuit protection enables higher reliability in most applications. The frequency adjustment pin allows the user to set the switching frequency from 200kHz to 3MHz, optimizing efficiency while minimizing external component size and cost. The LT3952 offers over 90% efficiency in a slim solution covering the board area while switching at a 2MHz frequency. The device comes in a heat-resistant and enhanced TSOP-28E package that provides a very compact, high-power LED driver solution.

     The LT3952 has a gate driver for PMOS LED switch-offs, providing a dimming ratio of up to 4,000:1 with an external PWM signal. For less demanding dimming requirements, the CTRL pin can be used to provide a 10:1 analog dimming range, and the internal PWM generator can be used to achieve 5:1 dimming. The LT3952's fixed-frequency, current-mode architecture provides stable operation over a wide range of supply and output voltages. 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 limiting and monitors.

     The LT3952EFE comes in a heat-resistant enhanced 28-lead TSSOP package. Three temperature grade versions are available: Extended temperature grade and Industrial temperature grade versions operate in the range of -40 °C to 125°C (junction temperature); The high-temperature version operates in the temperature range -40 °C to 150°C.