DC1582B-A: 50 ~ 400mV Ultralow Input Voltage Boost

Demonstration Circuit 1582B featuring the LTC3108 is a highly integrated DC/DC converter optimized for harvesting and managing energy from extremely low input voltage sources such as thermoelectric generators (TEG). The step-up topology operates from input voltages as low as 20mV.

The DC 1582B Demonstration Circuit has been optimized for low start-up voltage with a 100:1 turns ratio transformer. For application where it is desirable to trade-off a higher start-up voltage for higher current, a lower turns ratio transformer can be used. Refer to the LTC3108 datasheet for more information.

The LTC3108 is designed to accumulate and manage energy over a long period of time to enable short bursts of power to be used to acquire and transmit data. The burst must occur at a low enough duty cycle such that the total output energy during the burst does not exceed the average source power integrated over the accumulation time between bursts.

The Demonstration Circuit has been set up with a storage capacitor that makes it easy to evaluate the general functionality of the circuit. The lower value capacitor allows for a fast charge time but limits the pulsed energy that can be drawn from it. Space is provided, and alternate part footprints have been built into the PCB to allow experimentation with larger capacitors for more energy storage. In a typical application, the larger output capacitors may be used. Refer to the datasheet for more information including equations to properly size the output capacitors for a given application.

The LTC3108 is available in two versions, the only difference being the VOUT and VOUT2 output voltages. Refer to the datasheets for more information.