e-peas AEM20940 Thermal Energy Harvesting IC

The e-peas AEM20940 harvests the available input current up to 110mA while regulating the source to a voltage configured by the user. It integrates an ultra-low power boost converter to charge a storage element, such as a Li-ion battery, a thin-film battery, a supercapacitor or a conventional capacitor. The boost converter operates with input voltages ranging from 50mV to 3.5V. A unique cold-start circuit starts operating with empty storage elements at an input voltage as low as 380mV and an input power of only 100µW. Thanks to an external optional module, the cold start input voltage lowers to 60mV with an input power of just 150µW.

The low-voltage supply typically drives a microcontroller at 1.2V or 1.8V, and the high-voltage supply typically drives a radio transceiver at 1.8V, 2.5V, or 3.3V. Both are driven by highly efficient LDO (Low Drop-Out) linear regulators for low noise and high stability.

Configuration pins determine various operating modes by setting predefined conditions for the energy storage element (overcharge or over-discharge voltages) and by selecting the voltage of the high-voltage supply and the low-voltage supply.

The chip integrates all active elements to power a typical wireless sensor. Five capacitors and two inductors are required, all available in small packages. With only seven external components (external cold-start module not included), integration is maximized, and the footprint and BOM are minimized, optimizing the time-to-market and the costs of designs.