Differential channel circuit structure and method of transmitting signals by the differential channel
A differential channel circuit structure is disclosed. The differential channel circuit structure comprises a first differential circuit including a differential channel and a termination circuit. The differential channel has a differential mode impedance and a common mode impedance, and includes a first end and a second end, each capable of processing at least a first differential signal and a first common mode signal. The termination circuit includes a third end and a fourth end connected to the first end and the second end of the differential channel respectively, so as to simultaneously match the differential mode impedance and the common mode impedance of the differential channel.
1 . A method for constructing a signal transmission in a differential channel, the method comprising:
providing the differential channel having a differential mode impedance and a common mode impedance, wherein the differential channel includes a first end and a second end;
providing a termination circuit including a third end and a fourth end connected respectively to the first and second ends of the differential channel;
causing the termination circuit to simultaneously match the differential mode impedance and the common mode impedance of the differential channel;
providing a first input signal and a second input signal; and
forming a differential signal at the first end and the second end of the differential channel in response to the first input signal, and simultaneously forming a common mode signal at the first end and the second end of the differential channel in response to the second input signal, so that the differential signal and the common mode signal are superimposed on the first end and the second end, wherein:
the differential channel has an odd mode propagation delay, an even mode propagation delay, an odd mode impedance parameter, and an even mode impedance parameter, and the termination circuit has an impedance-matching parameter;
the impedance-matching parameter includes a first resistance value and a second resistance value; and
the method further comprises:
on a condition that the odd mode propagation delay and the even mode propagation delay are equal, determining a first predetermined number relationship between the odd mode impedance parameter and the even mode impedance parameter; and
on a condition that the differential channel and an impedance-matching terminal circuit are impedance matched, determining a second predetermined number relationship between the first resistance value and at least one of the odd mode impedance parameter and the even mode impedance parameter, and determining a third predetermined number relationship between the second resistance value and at least one of the odd mode impedance parameter and the even mode impedance parameter.