Step up converter runs from ultralow input voltage sources

1 min read

Linear Technology has announced an integrated step up dc/dc converter designed to start up and run from extremely low input voltage sources.

These sources include thermoelectric generators, thermopiles and small solar cells and, according to Linear, its self resonant topology steps up from input voltages as low as 20mV. The LTC3108 uses a small step up transformer and small temperature differences can be harvested and used to generate system power instead of traditional power. The energy harvesters are designed for applications requiring very low average power, but that need periodic pulses of higher load current. Its 2.2V ldo is designed to power an external microcontroller, while its main output is pin selectable to one of four fixed voltages to power a wireless transmitter or sensors. A second switched output can be enabled by the host in order to power devices that do not have a micropower shutdown capability. The addition of a storage capacitor is said to provide continuous power even when the energy source is unavailable. According to Linea, the LTC3108's quiescent current (<6µA) combined with an optimised design enables the 'fastest possible' charge times for the output reservoir capacitor.