Inductor based Circuit Techniques for Chip-to-Chip Interconnect and Standing Wave Clock Generation

There is few report of applying on-chip inductor to high-speed digital circuit, while it is useful passive element for RF circuit design. The on-chip inductor helps the digital circuit operate faster and can reduce the power consumption, because the inductance can cancel the capacitive load of the active device. In this manuscript, we present two conspicuous cases where on-chip inductor has been applied effectively in digital circuit design. One is spiral-inductor based wireless chip-interconnect. As an alternative of single chip system LSI, 3D-IC fabrication attracts attention and wireless chip-to-chip interconnects using capacitive and inductive coupling are now under development [1],[2]. They are expected to overcome the process cost and low yield problems of the silicon through-via technologies [3]. Another is over 10GHz clock generation and distribution using standing-wave network with inductively loaded. Global clock distribution becomes increasingly difficult for multi-GHz microprocessors, because skew and jitter are proportional to latency, which does not scale with clock period for the conventional tree network. Resonant techniques are expected to overcome the clock distribution problems [4]-[6].