Subracks and Systems: MicroTCA Expands the 19" Standard
Based on the MicroTCA standard Schroff has not only developed a product range with complete systems but also an entire subrack range. These subracks, constructed from only a few components in 3 U for Single AMC modules and in 4 U for Double AMC modules, consist of two side panels, cover and base plate as well as a rear panel. The hexagonal perforation in the cover and base plate guarantees maximum air circulation and stability at the same time. M3 threads are already integrated into the cover and base plate. The totally shielded subracks are available in 19", metric as well as in smaller dimensions for a lower number of AMC modules as Cube or Pico subracks. All of these subracks have a depth of 200 mm. The grid of the MicroTCA subrack is determined at 1 HP (5.08 mm), so that in a spacing of 1 HP the corresponding plastic board guides can retrospectively be clipped into the cover or base plate of the subracks. The die-cast part fixed to the lower, red part of the board guide serves to lock the inserted board. The upper board guides are green and equipped with an ESD clip. Further board guides in other colours are available, e. g. in yellow for Power module slots or blue for MCH slots. All three defined module widths, Compact (3 HP), Mid-size (4 HP) and Full-size (6 HP) are suitable and can be combined at will.
Schroff offers suitable backplanes in Star or Dual Star topology for all subracks, which support all defined protocols such as Gigabit-Ethernet, PCI Express, Rapid I/O, serialATA etc. For instance a possible backplane can support 9 AMC Full-size modules as well as 2 MicroTCA Carrier Hub (MCH) slots and 2 power module slots. The backplane is arranged in Dual Star topology. To drive the hard disks there are several S-ATA/SAS direct connections between the individual slots. In order to use the first available wider power modules on the market, both the power module slots have been arranged on the backplane at 9 HP. On the basis of this backplane other connection topologies can be realised fast and easily. Furthermore specific backplane layouts are available at request.
By omitting functions not required, which is possible with the MicroTCA standard, it is feasible to configure simple and cost effective solutions (Picture 2), which due to their technological advantages would be able to replace previous 19" PC or embedded solutions in industry. In this way future secure applications with small form factors are driven.
With cooling units from Schroff and additional accessories these simple subracks can easily be upgraded to a MicroTCA complete system. These complete systems for Single or Double AMC modules are equipped with exchangeable cooling units and filters, Dual Star backplane for redundant MCHs and room for redundant MicroTCA power supplies. Due to their flexibility and modularity in all aspects they can easily be adapted to different applications. The power supplies for the systems convert a range of AC inputs, -60 VDC, -48 VDC or 24 VDC, into the +12 V supply voltage defined for the AMC module. As low cost solution the MicroTCA power module (Single, Full-size) from Schroff combined with conventional plug-in or Open Frame power supplies handles the distribution and transfers the 12 V output voltage to the backplane. If redundancy or a higher performance is required a second power supply can be integrated. The MCHs (MicroTCA Carrier Hub) combine Hub and Shelf Management function in one plug-in unit.
Due to the openness of the standard, along with its modularity and scalability there will be many customer specific versions, which can easily be adapted from the described standard product range. For many years now, the development of customer specific solutions has been a successfully practiced enigneering service, to which the experts at Schroff contribute the necessary know-how and their vast experience in the most varied application areas.