A bidirectional universal serial bus (USB) includes switched terminations that are selectively activated to terminate the receiving end of the data bus in its characteristic impedance. The USB includes a twisted pair data cable that permits bidirectional data communication between a USB interface in a computer and a USB peripheral device. To control the bidirectional communication, the USB defines a transmit mode and a receive mode. Each end of the twisted pair data cable includes a selectively activatable switch termination that terminates the twisted pair data cable in its characteristic impedance when selectively activated. When the USB peripheral device is in the receive mode, the switched termination within the USB peripheral device is selectively activated so that the twisted pair data cable is terminated in its characteristic impedance. This reduces ringing and electromagnetic (EM) radiation on the twisted pair data cable. The switched termination within the USB interface in the computer is not activated when the USB interface is in the transmit mode. If the USB peripheral is placed in the transmit mode, and the USB interface in the computer is placed in the receive mode, the switched termination within the USB interface in the computer is selectively activated while the switched termination within the USB peripheral is placed in an inactive state. In this manner, the twisted pair data cable is always terminated in the proper impedance only at the receiving end.