More and more supercapacitors are being used as supplementary sources of energy in several applications. However, these capacitors, whose capacitances are measured in Farads, need special circuits. Linear Technologies presents an interesting circuit that can supply a load current of 150 mA from input voltages of 2.8 to 5.5 V. This circuit charges the capacitor with constant frequency and has the feature of automatic recharge. The circuit shown in the figure is for the charge of a 1.1 F capacitor.
