E-peas has announced an solar harvesting power management IC that can accept inputs from 5µA to 1A “spanning the full dynamic range of hybrid indoor-outdoor photo-voltaic cells”, it said.
“These hybrid PV cells have a wide power output that can vary from microwatts under indoor lighting to several watts when in direct sunlight,” the company explained.
With external components including mosfets and inductors, the IC, called AEM15820, can mediate power flow between a solar cell up to 4.34V, an external 5V power adapter, a storage element between 2.4 and 4.59V and a load between 600mV and 3.3V.
The above voltages are limited by the power converter topologies used, as power from the solar cell is handled through boost regulators, and power to the load is though a buck regulator.
Suitable storage elements include Li-ion, Li-po, LiFePO4 or NiMH cells, or a Li-ion capacitor. Configurable over-discharge and over-charge protection is provided, including options to extend the life of Li-ion cells, and, when charged from the 5V power input, charging can be either constant-current or constant-voltage constant-current.
When all stored power is depleted, the IC can cold-start from as little as 275mV if 5µW is available.
The output buck regulator for the application load can deliver up to 100mA and peaks at 96% efficiency.
This load can control the harvester over an I2C bus, and the chip provides a means to monitor average power.
“Average power monitoring allows the application circuit to get an estimate of the energy harvested from the
source to the battery and from the battery to the application circuit,” said e-peas. “A shipping mode is available to avoid charging and discharging the storage element during shipping or storage.”
E-peas is headquartered in Louvain-la-Neuve, Belgium, with offices in Switzerland and the USA. It has other harvesting ICs in production, and a low-power Cortex-M0 MCU.
See the 5µA to 1A photo-voltaic harvester at CES from 6th to 9th January next year in the Venetian Expo, level 2, stand 50752.
Find the AEM15820 data sheet on this e-peas web page – There is a lot going on in this chip, and this document is thorough, detailed, and easy to read.
