nVent Releases Next Generation nVent SCHROFF MicroTCA.4 Crate

nVent Electric plc announced the launch of its first MTCA.4 Crate by Revision 3.0 of the MTCA.0 base standard.

In September 2023, PICMG released Revision 3.0 of the MTCA.0 specification. This revision supports PCI Express Gen 4 and 5, as well as 100GBASE-KR4, to improve system performance by a factor of 4. To achieve these higher data rates, SMD and compression mount connectors have been evaluated by the NextGen MTCA working group, and the simulation results have served as a basis for defining the entire data transmission channel for MicroTCA. The transmission channel has been divided into logical parts to define the limits for boards and backplanes, ensuring all MTCA.0 Rev 3.0 MCHs, AMC’s, and Crates work together in a PCI Express Gen4/5 or 100 GbE environment.

As these high-end switches consume more power compared to their predecessors, the power budget for the MicroTCA Carrier Hub, where the switch resides, has been upgraded from 80 W to 110 W. To prevent overheating, the power budget of the cooling units was also upgraded to 110 W. A software mechanism helps ensure the backward compatibility of old and new MCHs, Power Modules, and Cooling Units.

In the Rear Transition Module (RTM), the improved 110W power limit is cooled with powerful fans and a superior cooling design.

The Cooling Unit firmware is based on revision 3.0 of the MicroTCA specification. When powered up, it remains at the 80W power rating. If the Power Module supports 110W per slot, the cooling unit will adjust accordingly. For Power Modules that only support 80W, if the IPMI communication is lost, it will remain within the 80W power envelope.

The Renesas H8S controller was previously used on the nVent SCHROFF MTCA.4 Crates have now been set to end of life. For this reason, nVent has introduced a new Cooling Unit Manager design based on the STM32 controller from STMicroelectronics, which includes the additional features described above.

To achieve the higher data bandwidth, the maximum trace length defined in MTCA.0 Rev. 3.0 needs to be matched. Therefore, the MCH slots moved from the outside to the middle of the card cage.

The PCB material has been upgraded to a lower-loss material with SMD connectors for superior performance. For optimized routing, the physical order of the AMC modules has been changed. In the past, the nVent SCHROFF MTCA.4 Crates used the physical order starting from 1 from left to right, now it’s changed into: 7-8-9-10-11-12-MCH1-MCH2-6-5-4-3-2-1.