US Patent 7474117 Bi-directional universal serial bus booster circuit

A method of transmitting a signal on a bi-directional universal serial bus (“USB”) circuit for boosting a signal on a USB bus disclosed. The circuit includes a first stage inverting buffer coupled to a second stage inverting buffer to form a non-inverting buffer circuit. A high pass filter is coupled in series with the non-inverting buffer circuit to provide AC coupling to the USB bus and to allow fast signal edges through the circuit. The booster circuit is arranged to improve signal quality over a USB bus to allow additional USB devices and longer USB busses to be utilized.