Active Terminator for Transmission Line
Original Publication Date: 1986-Mar-01
Included in the Prior Art Database: 2005-Mar-08
This article relates generally to transmission line termination and, more particularly, to the incorporation of active circuit devices to reduce power dissipation. Active switching devices in place of the usual resistive characteristic impedance terminators for transmission lines for binary signals can greatly decrease the average standby power dissipation. In the schematic binary circuit of Fig. 1, transmission line ZO is driven by push-pull driver Pu-Pd and terminated by the addition of controlled switches Su and Sd in series with respective resistors Ru and Rd on either side of node NR. Switch Su closes and switch Sd opens when node voltage is high. The switches function in the opposite manner when voltage is low.