'Energy-harvester' kan arbejde med 20mV spænding
Linear Technology præsenterer step-up DC/DC konverter og power manager, der kan operere med indgangspændinger helt ned til 20 mV (in english).
The world is going 'green'. Everywhere you look, engineers are coming up with new and innovative ways to harness non-traditional energy sources so that we can reduce greenhouse gas emissions so as to help save our planet.
These energy sources are all around us and include heat generated from a thermoelectric generator, vibration energy from a Piezo element, photovoltaic energy from sunlight and even galvanic energy from moisture.
The common term applied to these practices is 'energy harvesting' and it allows us to do things we’ve never done before. By simply taking these energy sources and converting them into the right voltage and current, it is possible to power remote sensors, or to charge up a storage device, such as a capacitor or thin film battery, so that a microprocessor or transmitter can be powered from a remote location without the need to have a mains power source locally.
However, the missing link in this equation has been a DC/DC converter (and power manager) that is capable of taking these extremely low levels of voltage and current and converting them to a level where they can have a practical use. That’s all about to change!
The new direction
Linear Technology adds the first in family of new energy harvesting products with best-in-class performance - the LTC3108 ultralow voltage step-up converter and power manager, that operates from inputs as low as 20mV.
The LTC3108 is a highly integrated DC/DC converter that is ideal for harvesting and managing surplus energy from extremely low input voltage sources such as thermoelectric generators (TEG), thermopiles and small solar cells.
Using a small step-up transformer, it provides a complete power management solution for wireless sensing and data acquisition. The onboard 2.2V LDO can power an external microprocessor, while its main output can be programmed to one of four fixed voltages to power a wireless transmitter or sensors. A storage capacitor provides power when the input voltage source is not available. Extremely low quiescent current and high efficiency design ensure the fastest possible charge times of the output reservoir capacitor.
Key features of the LTC3108
- Operates from inputs down to 20mV
- Complete energy harvesting power management system
- Selectable Vout of 2.35V, 3.3V, 4.1V or 5V
- LDO onboard: 2.2V at 3mA
- Logic controlled output
- Reserve energy output
- Power Good indicator
- Ultralow quiescent current: 6uA
- Uses compact step-up transformers
- Small 12-lead DFN (4mm x 3mm) or 16-lead SSOP packages
