June 24, 2014 – Linear Technology Korea (CEO Hong Sa-kwak) announced the launch of an integrated energy harvesting solution (product name: LTC3331) that provides a continuous output current of up to 50mA to extend battery life when utilizing harvestable energy. A simple 10mA shunt charges the rechargeable battery with harvested energy, while a battery cutoff function protects the battery from severe discharge. The LTC3331 requires only 200nA of power current from the battery when providing regulated power to the load from harvested energy, and only 950nA of operating current when running on the battery under no-load conditions.

The LTC3331 integrates a high-voltage energy harvesting power supply, a battery charger, and a synchronous buck-boost DC-DC converter powered by a rechargeable battery, generating simple, continuously regulated outputs for energy harvesting applications such as wireless sensor networks. The energy harvesting power supply includes a full-waveform bridge rectifier with AC or DC inputs and a high-efficiency buck converter, harvesting energy from piezoelectric (AC), solar (DC), and magnetic (AC) sources. When harvested energy is unavailable, the rechargeable battery input powers the buck-boost converter. This buck-boost converter operates over the full battery voltage range of up to 4.2V, regardless of whether the output is higher, lower, or equal to the current. The LTC3331 automatically switches to the battery when there are no longer any harvestable sources.

The energy harvesting input of the LTC3331 operates in a voltage range of 3V to 19V AC or DC and is ideal for use in piezoelectric, solar, and magnetic energy source arrays. These input low-voltage lockout threshold settings are programmable in the 3V and 18V ranges, allowing applications to operate the energy harvester at the peak current transfer point. Other features include pin-compatible output voltage and buck-boost peak current limiting, a supercapacitor balancer, and an input protected shunt (up to 25mA when VIN ≥ 20V).

The LTC3331EUH is available in a 5mm x 5mm QFN package, and the industrial temperature grade LTC3331IUH is currently available.

Photo Caption: Integrated Regulated Energy Harvesting Solution