The LTC4071 from Analog Devices is a Li-ion/Polymer Shunt Battery Charger System that allows simple charging of Li-ion or Polymer batteries from very low current, intermittent, or continuous charging sources. It requires an input voltage of 2.65 V. This battery charger consists of a near-zero current low battery latching disconnect function that protects even the lowest capacity batteries from deep discharge and potentially irreparable damage. It provides a charging current from 550 nA to 55 mA, which makes charging possible using previously unusable sources. This IC offers a unique architecture that requires only a single external resistor, resulting in a compact, low-profile footprint. It integrates a thermal battery qualifier to extend the battery lifetime and improves reliability by automatically reducing the battery float voltage at negative temperature coefficient (NTC) thermistor temperatures above 40°C.

This battery charger system also equips two-pin selectable low battery disconnect levels and a high battery status output to provide the charge status of the IC. It is available in a thermally-enhanced surface-mount package that measures 2 x 3 mm and is ideal for thin film batteries, energy scavenging/harvesting, solar power systems with back-up, memory back-up, and embedded automotive applications.