Design of AC-coupled circuit for high-speed interconnects

The scaling of semiconductor technology together with 3D IC stacking integration make it possible for many portable electronics to process large amount of multimedia data. AC-coupling enables chip placed face-to-face for signal transmission using close-field capacitive coupling. A high performance system design using AC coupled interconnect (ACCI) technology not only achieves shorter and faster interconnection between dies but also increases packaging density. This paper describes a chip-to-chip circuit design suitable for high-speed 3DIC interconnected applications. The AC-Coupled face-to-face (F2F) chip was simulated using HSPICE with TSMC 0.18-μm 1P6M CMOS technology process file under a 1.8 V supply voltage. The simulation results indicated the proposed circuit with the self-test characteristics can achieve differential signal transmission up to 2.5 Gbps.