Linear Technology’s LT3652 is a solar-power directed monolithic-buck battery charger integrated circuit for modern battery chemistries. It's available in a low-profile [0.75-mm (0.029-in)], 12-pin, 3 x 3 mm (0.12 x 0.12 in) DFN package. The LT3652’s input voltage regulation loop controls charge current to hold the input voltage at a programmed level. When connected to a solar panel, the device’s input regulation loop maintains the panel at peak output power. The LT3652 accepts a wide range of inputs from 4.95 to 32 V with a 40-V absolute-maximum rating for added system margin. The input voltage regulation loop also allows optimized charging from poorly regulated sources where the input can collapse under overcurrent conditions. The LT3652 charges a variety of battery pack configurations, including one to three lithium-ion/polymer cells in series, one to four lithium-iron phosphate cells in series, and sealed lead-acid batteries up to 14.4 V. Applications include 12- to 24-V automotive equipment, solar-powered systems, and battery chargers.