Pickering Interfaces, a supplier of modular signal switching and simulation solutions for use in electronic test and verification, has developed a family of low leakage switching solutions targeting very low current driven-guard measurements in semiconductor parametric test applications such as WAT (wafer acceptance testing). The cross-platform products include PXI, PXIe and LXI versions and are based on the switched guard design principle, with the overall designs assuring isolation resistances of up to 1013Ω.
The product family consists of three ranges providing various switching topologies. The PXI module, model 40–121, provides SPST (13 or 26) or 2:1 (8 or 16) multiplexer configurations. The PXI/PXIe modules, model 40–590 and model 42–590, deliver matrix (8×4 or 16×4) functionality, while the LXI, model 65–290, is based on Pickering’s established 2U LXI modular chassis (model 65–200) and accepts up to six 8×16 or 16×16 matrix plug-ins. Individual plugins are loaded into the front of the chassis, which is advantageous for expansion and maintenance.
To enable future test system scalability, PXI/PXIe models 40/42–590 and LXI model 65–290 products include loop-thru functionality, whereby the matrix size may be expanded by interconnecting adjacent modules in a chassis via short standard cables – the former permits expansion on the X-axis, and the latter enables both X and Y-axis expansion, facilitating flexible matrix sizes up to 16×96 per chassis with simple expansion into additional chassis. Each PXI module occupies just one chassis slot. This footprint is achieved using high-density coaxial connectors to support low–leakage–driven–guard measurements. The PXI model 40–121 modules utilize multiway MS-M connectors with all fifty-two pins (SPST configuration) distributed between just two connectors, significantly speeding up connect and disconnect operations. Models 40/42–590 and 65–290 families employ MMCX micro-miniature coaxial connectors with insulated covers, providing compact single ports that reduce wiring complexity and facilitate the simple loop-thru expansion of the matrix size.
The LXI model 65–200 platform also allows users to load pre-defined test sequences and increment them via software or hardware triggers, reducing test times compared to standard software driver control transactions. The sequences are stored on the LXI controller itself, reducing the burden on the Host CPU and Ethernet traffic and minimizing overall system latency. These features will optimize usage in semiconductor testing, where many thousands of tests may be required per DUT.
“All products employ custom-designed, high-quality ruthenium sputtered reed relays manufactured by our relay division, Pickering Electronics,” said Steve Edwards, Switching Product Manager at Pickering. “These switches feature an internal construction that maintains the necessary isolation for the new switched guard modules and ensures a long service life. Pickering also offers standard and custom cable solutions that can aid with integrating the products into users’ test systems.”
