e-peas AEM10941 Solar Energy Harvesting IC

e-peas AEM10941 Solar Energy Harvesting IC is an integrated energy management circuit that extracts DC power from up to 7-cell solar panels to simultaneously store energy in a rechargeable element and supply the system with two independent regulated voltages. The e-peas AEM10941 allows for extended battery lifetime and ultimately eliminates the primary energy storage element in a large range of wireless applications such as industrial monitoring, geolocation, home automation, e-health monitoring, and wireless sensor nodes.

The AEM10941 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 5V.

Its unique cold-start circuit can start operating with empty storage elements at an input voltage as low as 380 mV and an input power of only 3µW.

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 a configurable voltage between 1.8V and 4.1V. 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 overdischarge voltages), and by selecting the voltage of the high-voltage supply and the low-voltage supply. Moreover, special modes can be obtained at the expense of a few configuration resistors.

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, integration is maximized, and footprint and BOM are minimized, optimizing the time-to-market and the costs of designs.

Features

Ultra-low power start-up, cold start from 380mV input voltage and 3µW input power (typical)
Ultra-low power boost regulator
- Open-circuit voltage sensing for MPPT every 5s
- Configurable MPPT with 2-pin programming
- Selectable V_oc ratios of 70%, 75%, 85% or 90%
- Harvesting input voltage ranges from 50mV to 5V
- MPPT voltage operation ranges from 50mV to 4.5V
Integrated 1.2V/1.8V LDO regulator
- Up to 20mA load current
- Dynamically power-gated by external control
- Selectable output voltage
Integrated 1.8V-4.1V LDO regulator
- Up to 80mA load current with 300mV drop-out
- Dynamically power-gated by external control
- Selectable or adjustable output voltage

Flexible energy storage management
- Selectable or adjustable overcharge and over-discharge protection for any type of rechargeable battery or (super)capacitor
- Fast supercapacitor charging
- Indication when battery is running low
- Indication when output voltage regulators are available
Optional primary battery, automatic switching to primary battery when the secondary battery is exhausted
Integrated storage element balancing circuit for dual-cell supercapacitor