Figure 5. The MAX1879 high efficient Li+ charger for 1 Cell (3.7V) type battery
The MAX1879 initiates charging in one of three ways: battery insertion, charger power-up, or external manipulation of the THERM pin. CHG\ LED turns off when the on/off duty cycle falls to 1/8, and charging terminates when the on-chip counter times out. Key safety features include continuous voltage and temperature monitoring, a programmable charger time-out, and a 8mA precharge current mode to charge near-dead cells. Automatic detection of input power removal shuts down the device, minimizing current drain from the battery. An overall system accuracy of 0.75% ensures that the cell capacity is fully utilized without cycle life degradation.