Impedance stepping for increasing the operating speed of computer backplane busses

摘要

A computer interconnection backplane bus. The interconnection backplane bus is formed by bus transmission lines (61, 62, 63, 64, 65) and component connection transmission line sections (41, 42, 43, 44) that interconnect components (66, 67, 68, 69, 70, 71) of the computer. The characteristic impedance of the bus transmission lines (61, 62, 63, 64, 65) is stepped so that the number of impedance mismatches on the interconnection bus is minimized. The components (66, 67, 68, 69, 70, 71) of the computer are connected to the bus at the interconnections nodes (0, 1, 2, 3, 4, 5) of the bus transmission lines (61, 62, 63, 64, 65) through terminated component connection transmission line sections. The impedance mismatches that exist on the interconnection backplane bus are strategically placed so that the distortion to a transitioning voltage level edge is in the form of overshoot rather than under shoot or ringing.