CES Unveils New Energy Harvester for Small Solar Cells

E-peas, a leading technology company, has developed a groundbreaking energy harvesting integrated circuit (IC) specifically designed for hand-held remote controls and wireless keyboards equipped with small solar cells. This innovative IC allows for efficient energy conversion and utilization, ensuring optimal performance for these devices.

One of the key features of this energy harvesting IC is its ability to perform a cold start from an input voltage as low as 275mV, as long as a minimum power of 5µW is available. This capability ensures that the devices can operate even in low-light conditions, providing uninterrupted functionality.

The IC comes in two versions, each optimized for different types of solar cells to maximize energy harvesting:

The first version, AEM00920, regulates the photovoltaic terminal voltage to a fixed value, which is permanently programmed by the printed circuit board (PCB) to one of 32 values ranging from 250mV to 3.2V. This allows for precise control and efficient utilization of the available solar energy.

The second version, AEM10920, regulates the loaded photovoltaic terminal voltage to a fixed fraction of its open-circuit value. The open-circuit value is periodically measured by briefly unloading the solar cell. The AEM10920 offers eight fraction values between 35% and 90%, which can be programmed using three IC pads. Additionally, two pads allow for programming the period between open-circuit measurements (15 or 25 seconds) and the measurement duration (250 or 500ms).

Both versions of the IC feature a boost converter that increases the voltage at the solar cell to a level suitable for a storage element, such as a battery or supercapacitor. Furthermore, a 5V input is available to charge the storage element, providing an alternative power source.

The IC also includes a buck converter that takes the stored energy and delivers it to the device's output at selectable voltages of 2.2V, 2.5V, or 2.8V, with a maximum current of 135mA. This flexibility allows for compatibility with various devices and ensures efficient power delivery.

Both the boost converter and the buck converter in the IC have an impressive efficiency rating of above 90%, ensuring minimal energy loss during the conversion process.

For convenience during transport and storage, the IC features a shipping mode pad that allows for complete shutdown, conserving energy and extending the device's battery life.

The IC is packaged in a compact 4 x 4mm 24-pad QFN package, making it suitable for integration into small electronic devices.

The fixed input voltage version, AEM00920, is currently available for sampling, while the input-voltage tracking version, AEM10920, is scheduled for release in January 2024.

For more information about the AEM00920/10920 energy harvesting ICs, please visit the product page.

*The figures mentioned in this article are based on the data sheet, and e-peas has been contacted to confirm their accuracy.