Energy harvesting design board charges in 30 minutes
Alpha Micro has introduced an energy-harvesting evaluation kit for autonomous wireless sensors and other sub-100mW applications.
Developed by Infinite Power Solutions, the kit features the Thinergy MEC201 solid-state, rechargeable thin-film battery cell and the MAX17710 power-management IC from Maxim for energy harvesting and battery protection.
The credit card-sized board is designed to provide energy harvesting, storage and management functions.
The IPS-EVAL-EH-01 evaluation kit will accept charge currents less than 1µA, typically seen in energy harvesting.
An amorphous silicon photovoltaic solar array recharges the MEC201 to full charge in about 30 minutes in full sun and in approximately eight hours in typical office lighting (1,500 lux).
In addition, the board provides an interface to any type of external ambient energy-harvesting transducer. Example energy sources include light (captured by a variety of photovoltaic technologies), vibration (from a piezo-electric element), heat (via thermo-electric generator), and radio-frequencies (captured by a RF harvester or near-field communications (NFC) receiver.
The kit also features an interface header and 6-pin connector that are compatible with microcontroller and low power radio development kits available from suppliers such as Anaren, BlueRadios, Energy Micro, Microchip, Silicon Laboratories and Texas Instruments.
Harvested energy is stored in a 4V, 0.7 mAh capacity rechargeable thin-film battery.
The batteries can be stacked vertically in a parallel configuration for more power and capacity without consuming additional system footprint.
For example, a five cell MEC201 stack is approximately 1mm in total height and delivers 200mA of continuous discharge current (approximately 0.5W of power).
The MAX17710 power manager will operate on nanoamp currents and accepts energy from a variety of poorly regulated energy harvesting sources with output levels ranging from 1µW to 100mW.
The device integrates a programmable input boost regulator and needs no expensive external components to charge a MEC with energy sources as low as 0.8V. It protects the MEC by using a linear shunt-series regulator.
Applications for the kit include wireless sensors, biometric security systems, remote controls, memory and real-time clock back up.