The SM1201 consists of a step-up switching regulator controller and a low-dropout voltage regulator (LDO). The step-up switching regulator controller drives external MOSFET to provide the regulated supply voltage for LED strings of the LCD TV backlight unit. The switching frequency is programmable using an external resistor, and the LDO provides the logic voltage for the system. The device is optimized for thin-film transistor (TFT) liquid-crystal display (LCD) applications.