Patent ID: 7170259

Claim:
A charging apparatus for charging a rechargeable power source in a mobile device through a Universal Serial Bus (USB) port, comprising: a power converter configured to receive an input voltage from an external power source and generate a charger output having a regulated voltage; a signal generator configured to generate a charger configuration signal having a pre-selected frequency and duty-cycle, wherein the frequency and duty-cycle of the charger configuration signal are selected to identify operating characteristics of the charging apparatus, including at least the values of the regulated voltage an a maximum current capability of the charger output; and a USB connector for coupling the charger output and the charger configuration signal to the USB port of the mobile device, the USB connector having a voltage bus (Vbus) contact coupled to the charger output, a positive data (D+) contact coupled to the charger configuration signal, and a negative data (D−) contact coupled to the charger configuration signal, the charger configuration signal being transmitted simultaneously to the D+ and D− contacts, such that the D+ and D− contacts are continuously either both in a logic high state or both in a logic low state; wherein the mobile device is configured to identify the operating characteristics of the charging apparatus from the frequency and duty-cycle of the charger configuration signal and apply the charger output to recharge the rechargeable power source.