Terminations for Multi-Drop Bus Channels

This paper investi gates the potential benefits of usin g termination circuits with negative effective resistance for multi­ drop bus channels, whose applications include high-speed, high­ capacity memory interfaces. Signals propa gating throu gh multi­ drop channels can experience reflections at the split junctions, si gnificantly deg radin g the sig nal integ rity and limitin g the maximum data rates. Rather than passively matchin g the impedances at those junctions with resistors that lowers the si gnal swin g arrivin g at each receiver, a negative-resistance circuit that actively restores both the desired impedance and the si gnal swing is proposed. Measurement results demonstrate its feasibility and suggest that the active circuits distributed alon g the channel can also compensate the channel losses.