This application report shows how to operate the TPS61041 in a constant current LED drive configuration from input voltages less than 1.8 V. Although most applications using this device connect the VIN pin to the boost inductor, L1, as shown in Figure 1, this is not required. Separating the power stage from the control IC, allows the use of input voltages that are both above or below the operating range of these devices. The ability to operate from input
voltages less than 1.8 V allows these devices to operate from single cell alkaline, Ni-Cd, and Ni-Mh sources. This provides low cost solutions for applications such as backlight or indoor/outdoor lighting applications that require high efficiency to extend battery life.