From parallel to serial Moving from parallel SCSI technology to serial attach SCSI (SAS) technology has changed cabling schemes dramatically. The older parallel SCSI ran either single-ended or differential at rates up to 320 Mbits/s over 16 lanes. The latest SAS differential cable assemblies need to handle up to 6 Gbits/s on a single differential pair. The newest MiniSAS connector documented in the SAS-2 specification is even smaller for greater density. The latest mini-SAS connectors are half the size of the original SCSI connectors and 70% of the size of SAS connectors. Both SAS and Mini SAS have four lanes, compared to the original SCSI parallel cables. But along with higher speed, greater density, and flexibility comes greater complexity for the cable assemblies. With smaller connectors, the raw cable manufacturers, cable assembler, and the system designer must pay closer attention to the signal integrity parameters of the entire cable assembly.
Colin Bennett on 31 Mar 09Miniaturisation is not new, but manufacturing mechanical, electromechanical and fluidic components on a micro scale is rapidly developing into a recognisable industry in itself. Alistair Rae reports on a selection of the latest developments in this exciting field. Over the past few years a new industry has developed to serve the growing demand for micro-manufacturing. While miniaturisation has been ongoing since the commercialisation of the transistor some 50 years ago, it is only recently that it has been viable to manufacture high volumes of mechanical and electromechanical components with features in the sub-millimetre range.
