The AEM30940 is an integrated energy management subsystem that extracts DC power from AC source to simultaneously store energy in a rechargeable element and supply the system with two independent regulated voltages. This allows product designers and engineers to extend battery lifetime and ultimately get rid of the primary energy storage element in a large range of wireless applications like industrial monitoring, geolocation, home automation, wearables...
The AEM30940 harvests the available input power from 1 µW to 625 mW. It integrates an ultra-low-power Boost converter to charge a storage element, such as a Li-Ion battery, a thin film battery or a super- or conventional capacitor. The Boost converter operates with input voltages in a range of 50 mV to 4.5 V. With its unique cold-start circuit, it can start operating with an empty storage element at an input voltage as low as 380 mV and an input power of just 3 µW.
The low voltage supply typically drives a microcontroller at 1.8 V. The high voltage supply typically drives a radio transceiver at a configurable voltage. Both are driven by highly efficient LDO (Low Drop-Out) regulators for low noise and high stability.
Configuration pins determine various operating modes by setting predefined conditions for the energy storage element (overcharge or overdischarge), and by selecting the voltage of the high voltage supply. However, special modes can be obtained at the expense of a few configuration resistors.
The chip integrates all the active elements for powering a typical wireless sensor. With only seven external components, integration is maximum, footprint and BOM are minimum, optimizing the time-to-market and costs of WSN designs in all markets.
Five capacitors and two inductors are required, available respectively in the small 0402 and 0603 SMD formats. The AEM30940 comes with 28 pins, using space-saving quad-flat-no-leads packages (QFN).