Linear Technology introduced LTC3110, a bidirectional, programmable input current buck-boost supercapacitor charger with active charge balancing for 1- or 2-series supercapacitors. The proprietary low-noise buck-boost topology does the work of two separate switching regulators, saving size, cost and complexity.
The LTC3110 operates in two modes, backup and charge mode. In backup mode, the device maintains a system voltage, VSYS, of 1.71V to 5.25V, powered from the supercapacitor stored energy. Further, the supercapacitor storage input, VCAP, features a wide practical operating range from 5.5V down to 0.1V. This ensures that all practical stored supercapacitor energy is utilized, thereby extending backup times or shrinking the storage capacitors.
The device also features a charge-mode average input current limit that can be programmed up to 2A with +/-2% accuracy, preventing system power source overload while minimizing capacitor recharge time.