325 nA quiescent — the cold-start enabler
The Texas Instruments BQ25505RGRR is a power management IC purpose-built for energy harvesting. Its headline draw is a 325 nA supply current — low enough that the chip itself does not consume the micro-watts a small solar cell or thermoelectric generator produces. The input supply range of 0.12 V to 4 V means it can cold-start from a single photovoltaic cell or a TEG module at a fraction of a volt, then boost that to a regulated output for storage or load.