STMicroelectronics is opening new avenues for energy-harvesting applications with its latest IC integrating all the functions needed to power electronic circuits and recharge batteries using either a solar cell or Thermo-Electric Generator (TEG).
Harvesting ambient light or thermal energy to power small electronic devices such as wireless sensors, smart-building and industrial equipment controls, wellness and wearable monitors, protects the environment by reducing CO2 emissions, while eliminating batteries and power cabling, so finally enabling the Internet of Things (IoT) ecosystem. In the future, hundreds of millions of these devices operating from tiny quantities of harvested ambient energy are expected to be deployed in environments such as office buildings, houses, hotels, industrial sites, transportation infrastructure and electric vehicles.
ST’s SPV1050 is well suited for applications with power requirements from a few microwatts to several milliwatts, and is equally suitable for both indoor and outdoor consumer and industrial applications using either solar or thermal energy.
The low-power energy-harvesting IC also provides more functions than competing devices, which aids miniaturization and saves bill-of-materials costs. Both 1.8 V and 3.3 V regulators are available to power a companion microcontroller or wireless transmitter directly without requiring additional components. Maximum Power-Point Tracking (MPPT) continuously optimizes energy harvesting, or can be disabled. The battery-charging circuitry supports a wide variety of battery types including lithium-ion and lithium-polymer, lithium thin-film solid state, NiMH and NiCd, as well as supercapacitors.
“Energy harvesting delivers environmental benefits and helps reduce equipment ownership costs, and is used increasingly as energy-conversion efficiency rises and typical system power demands fall,” said Matteo Lo Presti, group vice president and general manager, Industrial and Power Conversion Division, STMicroelectronics. “The tremendous operational and energy-harvesting efficiency of the SPV1050, combined with its unparalleled flexibility and feature integration, enables engineers to realize many new opportunities in industrial and consumer markets.”
Inside the SPV1050, a buck-boost converter allows the device to connect to either TEG or indoor/outdoor solar-energy harvesting modules by providing a wide input-voltage range from 180mV to 8V. Average operating efficiency of 90 percent allows fast battery charging even at low input power levels, while minimum MPPT accuracy of 90 percent maximizes energy extraction from solar or TEG sources. In addition, the integrated battery-charging controller uses highly accurate under-voltage and end-of-charge thresholds, and provides safe control logic to prevent excessive discharging for longer battery life.
The SPV1050 is sampling now and scheduled for production in Q1 2014. It is available in a 20-lead QFN 3 by 3 by 1 mm package or in 20-bump WLCSP tested and unsawn wafers. Budgetary pricing is $1.15 for orders of up to 1,000 pieces.