DN0019, Smart dual-port USB charger with STCC2540 Design Note

As the USB became probably the most popular data and charging interface, a number of USB charged devices is still increasing. Thus it is a good solution to manufacture dual-port chargers, capable of simultaneous charging of two devices. The problem could be the management of charging current. Maximum charging current of small devices like smartphones is usually around 1 Amp, while for big devices such as tablets it is as much as 2.1 or 2.4 Amps. For two ports it would mean that the charger must be capable to deliver 4.2 - 4.8 Amps of current (21 - 24 Watts of power). On the other side, available space is usually limited and the same is valid for cooling, so it is not easy to develop a charger capable to simultaneously charge two tablets. Most powerful currently available USB chargers are usually capable of delivering 2.1 to 2.4 Amps