With the MP2481 from MPS (MONOLITHIC POWER SYSTEMS), the ideal IC for driving your white LEDs is now available, and it functions as a step-down or step-down/step-up converter.
Operating at up to 1.2A of output current and with a wide input voltage range, the device delivers excellent load and power regulation. Current regulated operation furthermore enables fast regulation characteristics and ease of stabilization. Either a DC signal or a PWM signal at the control input can be used to regulate brightness.

Specifications in Brief:

• Buck or buck/boost operation
• Wide input voltage range of 4.5V - 36V
• Output current of up to 1.2A
• Internal 0.30? power MOSFET
• 1.4MHz switching frequency
• Regulation: analog or PWM
• Up to 95% efficiency
• 0.5µA current consumption during shut-down mode
• Ceramic capacitors for stability
• Internal protection against overload, temperature, open LED chains, overvoltage and short circuits

A15