A USB chipset coupled between a first device and a second device is provided. A data processing unit is coupled to the first device and generates a plurality of transmission information according to first information provided by the first device. A transmitting unit is coupled to the data processing unit to transmit the transmission information to the second device and includes a converting module, a first output driving module, a second output driving module, and a transmitting-terminal selecting module. The converting module is coupled to the data processing unit to receive the transmission information in parallel and serially outputs the transmission information. The first output driving module is coupled to a first pin set. The second output driving module is coupled to a second pin set. The transmitting-terminal selecting module is coupled between the converting module and the first and second output driving modules.