The chip harvests energy from thermoelectric generators (TEGs) and thermopiles when these sources are available.
An internal boost converter, combined with a small step-up transformer, harvests energy from input voltages as low as 20mV, commonly found from sources such as TEGs and thermopiles, and delivers an output which tracks the battery voltage. An additional 2.2V low-dropout regulator provides power to the external IC. If harvested energy is not available, the system is powered directly from the battery, requiring only 6-microamps.
The LTC3107 is designed to use the primary battery to start up the IC and power Vout and the LDO with or without any available power from the energy harvesting source. When the energy harvest source is available, the LT3107 seamlessly transitions to run only from the energy harvest source with only 80nA of quiescent current drawn from the primary battery. If the energy harvest source goes away or if the load exceeds the energy harvested, the LT3017 transitions to the primary battery to supply the VOUT and VLDO loads. The BATT_OFF indicator can be used to track the battery usage.
The LTC3107EDD is offered in a 3mm x 3mm 10-lead DFN package, priced starting at $2.95 each for 1,000-piece quantities. An industrial grade version, the LTC3107IDD, is guaranteed to operate over the -40°C to 125°C and is priced starting at $3.45 each in 1,000-piece quantities.
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