Low-power circuits enable next wave of energy harvesting

The bq25570 , bq25505 , TPS62740, TPS62737, and TPS62736 are next-generation power management ICs that acquire and manage uW to mW of power harvested from light, heat, or mechanical energy sources. They maintain the industry’s lowest levels of active quiescent current and enable battery-free operation to wireless sensor networks, monitoring systems, wearable medical devices, mobile accessories, and other applications with limited access to power.

The bq25570 boost charger with an integrated buck converter consumes 488-nA quiescent current and achieves greater than 90% efficiency at output currents lower than 10 μA. It features maximum power point tracking (MPPT) to extract and manage power from photovoltaic cells and thermoelectric generators, and supports any energy storage element, such as a rechargeable Li-iIon battery, thin-film battery, supercapacitor, or conventional capacitor. The bq25505 achieves active quiescent current of 325 nA and features an autonomous power multiplexor gate drive that enables seamless system operation from energy-harvesting sources and the primary battery. The TPS62740 is the smallest and lowest-power buck converter for 300-mA output current designs, providing 360 nA of quiescent current during active operation and 70 nA during standby. It achieves >90% efficiency down to 10 μA. The TPS62737 converter suits 200-mA designs and the TPS62736 targets 50-mA designs. They provide 370-nA quiescent current during active operation and 15 nA during sleep, while achieving 90% efficiency at output currents lower than 15 μA.