Low Propagation Delay Load-Balanced 4 x 4 Switch Fabric IC in 0.13-μm CMOS Technology

A load-balanced Birkhoff-von Neumann (LB-BvN) 4 x 4 switch fabric IC is proposed for feedback-based switch systems. This is fabricated in 0.13-mu m CMOS technology and the chip area is 1.380 x 1.080 mm(2). The overall data rate of the LB-BvN 4 x 4 switch fabric IC is up to 32 Gb/s (8 Gb/s/channel) with only 0.8 ns propagation delay. The LB-BvN switch is highly recommended for constructing the next-generation terabit switch. In a feedback-based switch system, the long propagation delay of the switch module reduces the system throughput significantly. In this paper, we present a scalable LB-BvN 4x4 switch fabric IC directly in the high-speed domain. By observing the deterministic switching pattern of the N x N LB-BvN switch, we present a low-complexity pattern generator that reduces the PG complexity from O(N-3) to O(1). This technique reduces the propagation delay of the switch module from 30 to 0.8 ns, and also provides 80% area saving and 85% power saving compared to serializer-deserializer interfaces. The proposed LB-BvN 4x4 switch fabric IC is suitable for feedback-based switch systems to solve the throughput degradation problem.