US Patent 8242742 Chargers, systems and methods for detecting a power source

A charger includes a detection pin, a voltage divider, and a comparator. The detection pin can couple the charger to a power source via a first data line. The voltage divider and the comparator are coupled to the detection pin. The voltage divider divides a power voltage provided by the power source and provides a detection voltage at the detection pin. The comparator compares the detection voltage with a predetermined reference voltage and identifies a type of the power source according to the comparing.