Renesas has developed an energy-harvesting embedded controller that can eliminate batteries in IoT devices. Based on Renesas’ SOTB (silicon–on–thin–buried–oxide) technology it uses a 32-bit, Arm Cortex-based embedded controller capable of operating up to 64 MHz while consuming 20 μA/MHz active current and 150 nA deep standby current.
The R7F0E is a configurable Energy Harvest Controller (EHC) function which enables direct connection to many different types of ambient energy sources, such as solar, vibration, or piezoelectric, while protecting against harmful inrush current at start-up.
The EHC also manages the charging of external power storage devices such as supercapacitors or optional rechargeable batteries. Other low power techniques are
(1) to sense and capture external analogue signals at all times because the 14-bit ADC consumes 3 uA current,
(2) to retain up to 256 KB of SRAM data content while consuming one nA per each KB of SRAM, and
(3) to provide graphics data conversion including rotation, scroll, and colorization by incorporating sophisticated low power hardware techniques for driving an external display using Memory-In-Pixel LCD technology that consumes virtually no power to retain an image.
