COMPETITION

Reader wins Molex iPass x4 External PCI Express Test Kit

Helén L Holmgren, a purchaser at Diatron AB in Sweden, has won the Molex test kit competition from Arrow Innovation issue 10. The competition, which was to mark the availability of its iPass I/O plug-in connector system for high-speed serial-parallel data transmission, sees Helén win a test kit that combines test boards, cable assemblies, connectors and shielded cages.



Progressive increases in hard disk capacities demand high-speed data transmission to hard disk memory. While the SATA (Serial Advanced Technology Attachment SCSI) interface standard 1.0, defined in 2000, requires 1.5Gbps per lane (differential signal pair), many simple SATA plug-in connectors are unable to cope with this speed. Furthermore, second generation SATA (defined in 2004) requires 3.0Gbps - and a further increase in data rates is foreseeable! Additionally, the current generation of fibre channel products offers data rates of 4.25Gbps, with 8.5Gbps products already in development.

All these standards use 8B/10B coding to realise serial-parallel transmission. This coding makes it possible to recognise the bits of a word being transmitted on individual Twinax cables with varying delay times. The semiconductor industry has developed a variety of chips for transmission via a backplane using 8B/10B coding to enable data rates from 3Gbps to 6Gbps in serial-parallel transmission mode.

To support these developments requires an I/O plug-in connector system that provides transmission of several ‘lanes’ of serial-parallel data at rates in excess of 10Gbps. It has become customary to classify such connectors using ‘x + x * Gbps’ notation. Consequently, a 4 + 4 * 10Gbps I/O connector has a total bandwidth of 80Gbps, 40Gbps is transmitted in parallel via four Twinax cables each with 10Gbps serial transmission and 40Gbps is received in parallel via four Twinax cables each with 10Gbps and then re-assembled.



The Molex solution was to take the 0.8mm system (developed in the course of the Z axis plug connector) out of the drawer and move the upper and lower row by half a grid in order to minimise cross-talk between the contacts. The result is the iPass I/O plug-in connector system, which is available for SAS/SATA, fibre channel and External PCI-Express.

Molex iPass Plug-in Connector System Features:

• Ruggedised connector housing (diecast) with positive locking feature
• Unlock by simply pulling ‘lanyard’ tag
• Three hot pluggable contact levels
• Pick and place SMT daughter card connector in tape and reel
• Diecast housing with inspection cover in 1-, 2- or 4-port versions
• EMC shielding to the front panel by means of a conductive rubber ring
• Polarisation system
• Coding ribs prevent a same size connector plugging into the wrong interface in multi-bus systems

The external iPass system with 26, 36, 50, or 2*68 circuits electrically enables 4 + 4 * 10Gbps (26-size as Mini SAS 4x and 36-size as Mini SAS 4i with sidebands 0 through 7) and 8 + 8 * 10Gbps (50-size as 8x PCIe) or 16 + 16 * 10Gbps (2*68 size as 16x PCIe).

These interfaces are described in the Serial Attached SCSI - 1.1 (SAS-1.1) standard or in the PCI Express® specifications. SAS applications also require lower cost plug-in systems for applications within the devices, as realised in the internal iPass system in 26 and 36 circuit designs.



To help users develop applications based on the iPass family, Molex has developed a number of test kits that bring together boards, cable assemblies, connectors and shielded cages.