Work out impedance matching termination instantly with clear inputs, formula shown and shareable results.
Series termination adds Z0 minus the driver impedance at the source and dissipates no static power, but only works point to point. Parallel termination at the receiver matches the line for multi-drop and better signal fidelity, at the cost of continuous DC current.
Termination
series R = Z0 - Zdriver; parallel R = Z0; Thevenin uses two resistors of 2 Z0; reflection = (ZL - Z0)/(ZL + Z0)
Series for point-to-point CMOS signalling where power matters. Parallel or Thevenin for multi-drop buses and high-speed links where reflections must be killed at the far end.
A series capacitor blocks DC, so the resistor only damps transitions. The trade is a frequency-dependent match and a settling time constant.