Highly efficient, regulated dual-output, ambient energy manager for AC or DC sources with optional primary battery

The AEM30940 is an integrated energy management circuit that extracts DC power from a piezo generator, a micro turbine generator or any high frequency RF input to simultaneously store energy in a rechargeable element and supply the system with two independent regulated voltages. The AEM30940 allows to extend battery lifetime and ultimately eliminates the primary energy storage element in a large range of wireless applications such as industrial monitoring, home automation, transportation and smart agriculture.

The AEM30940 harvests the available input current up to 110 mA. 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 in a range from 50 mV to 5 V. With its unique cold start circuit, it can start operating with empty storage elements at an input voltage as low as 380 mVand an input power of just 3 µW.

The low-voltage supply typically drives a microcontroller at 1.2 V or 1.8 V. The high-voltage supply typically drives a radio transceiver at a configurable voltage between 1.8 V and 4.1 V. Both are driven by highly-efficient LDO (Low DropOut) 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 the active elements for powering a typical wireless sensor. Five capacitors and two inductors are required, available in the small 0402 and 0603 size, respectively. With only seven external components, integration is maximum, footprint and BOM are minimum, optimizing the timeto-market and the costs of WSN designs

Features:

Ultra-low-power start-up:

• Cold start from 380 mV input voltage and 3 µW input power (typical)
• RF input power from -18.5 dBm up to 10 dBm (typical)

Ultra-low-power boost regulator:

• Open-circuit voltage sensing for MPPT every 0.33 s
• Configurable MPPT with 2-pin programming
• Selectable Voc ratios of 50, 65 or 80%
• Input voltage operation range from 50 mV to 5 V
• MPPT voltage operation range from 50 mV to 5 V
• Constant impedance Matching (ZMPPT)

Integrated 1.2/1.8 V LDO regulator:

• Up to 20 mA load current
• Power gated dynamically by external control
• Selectable output voltage

Integrated 1.8 V-4.1 V LDO regulator:

• Up to 80 mA load current with 300 mV drop-out
• Power gated dynamically by external control
• Selectable or adjustable output voltage

Flexible energy storage management:

• Selectable overcharge and overdischarge protection
• For any type of rechargeable battery or (super)capacitor
• Fast supercapacitor charging
• Warns the load when the battery is running low
• Warns when output voltage regulators are available

Smallest footprint, smallest BOM:

• Only seven passive external components

Optional primary battery:

• Automatically switches to the primary the battery when the secondary battery is exhausted

Integrated balun for dual-cell supercapacitor

Documents

 AEM30940 Datasheet

 AEM30940 Product Brief