An integrated circuit includes a termination for a transmission line having a predetermined characteristic impedance. The termination includes a controllable impedance circuit, including a multiplier, coupled to the transmission line. A reference impedance, placed external to the integrated circuit, has an impedance related to the characteristic impedance of the transmission line. A control circuit is coupled between the reference impedance and the controllable impedance circuit, and conditions the controllable impedance circuit to have the characteristic impedance responsive to the reference impedance