Linear Technology (www.linear.com) has in its component line the LT3518, recently launched, which consists of a driver for LEDs capable of supplying an output current of 2.3 A. In addition to already including an internal switch of 2 .3 V x 45 V, this component has a 3000: 1 PWM True Color intensity adjustment range, and a 100 mV, high-side current sensor. Other features of the integrated circuit are its adjustable switching frequency range between 250 kHz and 2.5 MHz and a protection against open LED. The operating voltage range is from 3 V to 30 V. The circuit can operate in boost, buck or buck-boost mode. The circuit also has protection against transients up to 40 V. In figure 1 we have the application circuit suggested by Linear, which can be used in background lighting, panels for automotive use, lighting and scanners. The efficiency of the circuit exceeds 90%. More information about the LT3518, including different application circuits, can be found on the data sheet available in PDF format on the company's website.
