LTC3109
Auto-Polarity, Ultralow
Voltage Step-Up Converter
and Power Manager
Description Features Operates from Inputs as Low as ±30mV
n Less Than ±1°C Needed Across TEG to Harvest
Energy
n Proprietary Auto-Polarity Architecture
n Complete Energy Harvesting Power Management
System – Selectable VOUT of 2.35V, 3.3V, 4.1V or 5V – 2.2V, 5mA LDO – Logic-Controlled Output – Energy Storage Capability for Operation During Power Interruptio Power Good Indicator
n Uses Compact Step-up Transformers
n Small, 20-lead (4mm × 4mm) QFN Package or 20-Lead SSOP The LTC®3109 is a highly integrated DC/DC converter ideal
for harvesting surplus energy from extremely low input
voltage sources such as TEGs (thermoelectric generators) and thermopiles. Its unique, proprietary autopolarity
topology* allows it to operate from input voltages as low
as 30mV, regardless of polarity. n Using two compact step-up transformers and external
energy storage elements, the LTC3109 provides a complete power management solution for wireless sensing
and data acquisition. The 2.2V LDO can power an external
microprocessor, while the main output can be programmed
to one of four fixed voltages. The power good indicator
signals that the main output is within regulation. A second
output can be enabled by the host. A storage capacitor (or
battery) can also be charged to provide power when the …