e-peas – Highly-Efficient Regulated Dual-Output, Ambient Energy Manager for High Frequency RF input with optional primary battery
The AEM40940 is an integrated energy management subsystem that extracts AC power from high frequency RF inputs. The AEM40940 harvests the available AC input power from – 19dBm up to 0dBm thanks to an integrated high frequency rectifier. 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 from 50 mV to 2.5V. With its unique cold-start circuit, it can start operating with empty storage elements at an input power of just -19dBm.
The low voltage supply typically drives a microcontroller at 1.2V or 1.8 V. The high voltage supply may typically drive 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 voltages), and by selecting the voltage of the high voltage supply. Moreover, 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 the costs of WSN designs in all markets.
Five capacitors and two inductors as well as the matching network passive components are required, available respectively in the small 0402 and 0603 SMD formats.