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Product Focus
Energy Harvesting
Page 2
In September, Texas Instruments Inc. (TI) introduced a high-efficiency, ultra-low power step-down converter for energy harvesting and low-power applications. The new TPS62120 achieves 96% efficiency, and can generate a 75mA output current from an input voltage of 2 to 15V. The device supports energy harvesting and battery-powered applications, as well as 9 and 12V line-powered systems.
The TPS62120 synchronous converter features a power save mode to provide high efficiency over the entire load current range, reaching 75% efficiency at loads down to 100µA. During light load operation, the device operates in a pulse frequency modulation (PFM) mode, consuming only 11µA of quiescent current. The TPS62120 also maintains smooth, efficient operation at higher currents by transitioning automatically from its power save mode to a fixed-frequency pulse width modulation (PWM) mode.
In November, Nextreme Thermal Solutions announced the availability of the new eTEG™ HV37 thermoelectric power generator, the next entry in the high-voltage (HV) series of clean energy generators based on thin-film thermoelectrics. The eTEG HV37 converts waste heat into electrical energy for a variety of self-powered applications in the wireless sensor, automotive, aerospace, industrial and medical device markets. The eTEG HV37 joins Nextreme’s other power generators, the eTEG HV56 and HV14, to offer a complete line of thermoelectrics that address a range of power and voltage requirements.
The eTEG HV37 is capable of producing 1.0mW of output power and an open circuit voltage of 170mV at a 10K ΔT in a footprint of only 6mm2. At 50K ΔT, the HV37 produces 24mW of power and an open circuit voltage of 850mV. The module is extremely thin: only 0.6mm high, and can be configured electrically in series to produce higher voltage and power outputs.
Powercast Corp. also announced its Lifetime Power® Energy Harvesting Development Kit for Battery Charging in November. The kit features near-loss-less energy storage and efficient charging via the THINERGYµ Micro-Energy Cell (MEC), a solid-state, rechargeable thin-film micro-battery from Infinite Power Solutions (IPS).
The Lifetime Power Energy Harvesting Development Kit for Battery Charging is composed of a 3W Powercaster™ transmitter, a P2110 Powerharvester® receiver evaluation board, a custom-designed battery-charging board, a 1mAh THINERGY MEC evaluation card and other accessories. The kit makes it easy to prototype and develop rechargeable battery-based micro-power systems such as wireless sensor networks that are reliably and perpetually powered by radio waves – eliminating the expense and hassle of traditional battery replacement. The Texas Instruments eZ430-RF2500 wireless development tool is also included as a demonstration application.
In December, Fujitsu Laboratories announced the development of a new hybrid harvesting device that captures energy from either light or heat, which are the most typical forms of ambient energy available for wide-scope application. This makes it possible for a single device to capture energy from either heat or light without combining two harvesting devices. In addition, as it can be manufactured from inexpensive organic materials, device production costs can remain low.
By changing the electrical circuits connecting two types of semiconductor materials – P-type and N-type semiconductors – the device can function as a photovoltaic cell or thermoelectric generator.
Fujitsu Laboratories successfully developed an organic material that is suitable for a generator in both photovoltaic and thermoelectric modes. The organic material features a high generating efficiency that can produce power from even indoor lighting in photovoltaic mode, and it can also generate power from heat in thermoelectric mode. Since the organic material and its process cost are inexpensive, production costs can be greatly reduced.