Fast, High Effi ciency, Standalone NiMH/NiCd Battery Charging CircuitFigure 1 shows a fast, 2A charger featuring the high effi ciency LTC4011 550kHz synchronous buck converter. The LTC4011 simplifies charger design by integrating all of the features needed to charge Ni-based batteries, including constant current control circuitry, charge termination, automatic trickle and top off charge, automatic recharge, programmable timer, PowerPath control and multiple status outputs. Such a high level of integration lowers the component count, enabling a complete charger to occupy less than 4cm2 of board area. more
Battery Charger Delivers 2.5A With >96% Efficiency
Battery chargers are usually designed without regard for efficiency, but the heat generated by low-efficiency chargers can present a problem. For those applications, the charger of Figure 1 delivers 2.5A with efficiency as high as 96%. It can charge a battery of one to six cells while operating from a car battery.Figure 1. Modified feedback paths transform this switch-mode power-supply circuit for notebook computers into a high-efficiency battery charger. more pdf