Energy-harvesting kit suits wireless sensing

Infinite Power Solutions Inc. announces availability of the IPS-EVAL-EH-01, a universal energy-harvesting evaluation kit suited to autonomous wireless sensors and other sub-100 mW applications. The new kit includes the company's THINERGY MEC101 solid-state, rechargeable, micro-energy cell, a type of thin-film battery. The kit also features the MAX17710 from Maxim Integrated Products, a complete power-management IC product for energy harvesting and battery protection.

The kit helps design engineers develop and evaluate self-sustaining power supply solutions without using conventional batteries and supercapacitors that require frequent replacement. It can also be used to power third-party micro-controller and radio module development kits, letting designers create and evaluate a range of self-powered microelectronic applications.

The IPS-EVAL-EH-01 circuit board footprint is about the size of a credit card and contains three key elements -- energy harvesting, storage, and management. Due to the ultra-low quiescent current of the integrated PMIC, and the low self-discharge rate of the integrated THINERGY MEC101, the IPS-EVAL-EH-01 evaluation kit accepts charge currents less than one microampere, making it suitable for storing harvested energy. An amorphous silicon photovoltaic solar array is integrated for plug-and-play use and recharges the MEC101 to a 100% state of charge in about 30 minutes in full sun and in about 8 hours in typical office lighting.

The board also provides an interface to any type of external ambient energy-harvesting transducer. Example energy sources include light (captured by 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 popular micro-controller and low power radio development kits available from a semiconductor and module manufacturers such as Anaren, BlueRadios, Energy Micro, Microchip, Silicon Laboratories, and Texas Instruments.

Harvested energy is efficiently stored in a THINERGY MEC101-7S, which is a 4V, 0.7 mAh capacity rechargeable battery suited for energy-harvesting applications. The MEC101-7S is a thin, flexible, solid-state, and near loss-less energy storage cell about the size of a postage stamp. Self-discharge is reportedly so low and insignificant that energy can be reliably stored for decades on a single charge. The MEC101 can recharge to 90% in just 15 minutes and can be recharged more than 10,000 times. With an expected lifetime of up to 20 years, THINERGY MECs require no maintenance or periodic replacement compared to other batteries and supercapacitors. THINERGY MECs contain no heavy metals.

Efficient energy management is achieved by the MAX17710 PMIC, an IC that integrates all power-management functions for ambient energy harvesting, charging, and protecting THINERGY MECs. Operating at an ultra-low current level measured in nanoamps, the MAX17710 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 0.8 V. It protects the MEC by using a linear shunt-series regulator.

An integrated, ultra-low-quiescent current, adjustable low-dropout linear regulator (LDO) with selectable voltages of 3.3, 2.3, or 1.8 V allows the MAX17710 to adapt to a variety of loads. Applications for this combination of energy harvester, THINERGY MEC, and MAX17710 PMIC include remote/autonomously powered wireless sensors, biometric security systems, remote controls, memory and real-time clock (RTC) back up, asset tracking, semi-active RFID tags, powered smart cards, smart home and building energy-management, machine monitoring systems, medical applications, and portable consumer electronics.

For more information, contact Infinite Power Solutions Inc., 11149 Bradford Rd., Littleton, CO 80127. Phone: (303) 749-4800.