Maria Montero

e-peas announces PMIC for energy harvesting from thermoelectric generators

e-peas launches the PMIC AEM20940, which allows the collection of energy from thermoelectric generators.

This week, e-peas announced the AEM2094, an IC that can draw and control up to 110 mA from thermoelectric generators (TEG). Remote IoT nodes never need battery replacement.

The AEM20940 on a PCB. Image from e-peas

This PMIC is designed to help engineers take advantage of an often-overlooked power source that might as well be available at the site of an IoT node. That untapped potential source is heat, which is converted into electricity through a process called thermoelectric generation.

How does thermoelectric generation work?

A temperature gradient is present when one side of an appropriate surface is hotter than the other side. Heat will flow from the hotter side to the cooler side, causing the charge carriers to move. This creates a voltage difference between the two edges and can generate a not insignificant amount of electrical energy.

Image from e-peas

The left side of the diagram above illustrates the TEG which is the source of electrical power. The center of the diagram is the e-pease IC that controls the disbursement of that power.

Advantages conferred through the AEM20940

One of the main benefits of IoT is the ability to monitor conditions at points that are difficult to access or even dangerous for personnel who would otherwise take over the work. But those benefits are compromised if you need to periodically enter those areas to change batteries.

An e-pease AEM20940 controlled thermoelectric generator can eliminate the need to change batteries in remote, inaccessible and potentially dangerous sites of IoT nodes.

Diagram of the AEM20940. Image of the technical sheet.

Geoffroy Gosset, co-founder and CEO of e-peas goes a step further when he explains that “it means that our customers will be able to design IoT systems that can extract energy from their surrounding environment, regardless of the available sources.”

AEM20940 Evaluation Board and Specifications

The AEM20940 is available in 28mm by 5mm and 5mm QFN packages. It is capable of extracting power from sources that generate up to 110 mA. It will monitor the storage of electricity in external rechargeable elements of easy choice. It will also simultaneously supply power to the system through two different regulated voltages:

  • 1.2 / 1.8V, used to power the system microcontroller
  • 2.5 / 3.3V, used for RF transceiver

The evaluation board for the AEM20940. Image from e-peas via Publitek

It will only require external power during cold start, either:

  • 100mV input voltage and 80μW input power with optional external module (typical)
  • 380 mV 3μW input power without optional external module (typical)

A detailed product sheet for the AEM20940 can be found here.

Other PMICs for the use of thermal energy and energy on the market

  • Analog Devices offers a range of chips to manage energy harvesting from thermoelectric, solar, and other sources, as detailed here. An example is the LTC3109 for TEG.
  • STMicroelectronics offers the SPV1050, which also works with sources such as TEG. It offers output voltages in the 1.8V and 3.3V ranges, as well as an unregulated output.
  • Maxim Integrated offers the MAZ17710 for power harvesting. Provides a selected regulated 3.3V, 2.3V or 1.8V output.

Have you ever worked on an application that required TEG? What specifications were the most important to you in your selection of components? Share your experiences in the comments below.