New 3U VITA 62-compliant PSU Meets Power and Reliability Demands

Aitech Defense Systems Inc. has expanded its line of power supply units (PSUs) with the P233, designed to meet the demands of highly integrated embedded systems. The 3U VITA 62-compliant PSU offers an output capacity of up to 500 W as well as a wide voltage input range of 18 VDC to 32 VDC, and can be used in a range of VME, VPX and CompactPCI systems.

Two P233 power supplies can be connected in parallel with a load sharing option to provide 1,000 W of total output power. Or, for added system reliability and redundancy, the connected units can function as two parallel, redundant 500 W supplies with auto-failover.

The MIL-STD-704-compliant P233 features six supply outputs: 3.3V, +12V, +5V, ±12V AUX and +3.3V AUX, each with independent current limiting as well as numerous protection mechanisms to ensure the PSU will not be damaged, even if connected to an incorrect or malfunctioning power source. Complete with internal built-in test (BIT) and input line filters that protect from input power overvoltage, surges and reverse polarity, the P233 provides exceptional reliability.

Input-to-output isolation eliminates ground loops, and the main high output supplies (3.3V, +12V, +5V) offer remote sense lines for voltage stability in high current loads. An optional non-electrolytic capacitor power hold-up module provides full rated output power for 25 mS. An external capacitor bank can also be added to provide up to 50 mS power hold-up at a full-rated 500 W output power with a proportionally longer holdup time at reduced output loads.

The power supply board has no minimum load requirement, which ensures stable output voltages over the full range of power output.

The extensive BIT in the FPGA monitors input and output voltages, output currents and power supply temperature which are used to trigger the various protection mechanisms. An electronic Elapsed Time Recorder measures the total time the P233 has been operating. A BIT Fault Log captures operational anomalies should they occur.

An Intelligent Platform Management Interface (IPMI) provides the ability for the system processor to interrogate all these features and functions without affecting the power supply’s operation.

Emil Kheyfets, director of military & aerospace product management at Aitech, noted, “There’s a direct correlation to the density of electronics in an embedded system and the number of functions that system is tasked with performing. And it all requires power…reliable, intelligent, versatile power. We’re developing these units to meet not only industry standard requirements, but the needs of the systems themselves.”

The P233 supports the standard ENABLE#, INHIBIT#, FAIL# and SYSRESET# control signals. The ENABLE# and INHIBIT# pins can be used to enable the 3.3V_AUX output independently of the remaining output voltages. This can be useful for systems with system management functions that require 3.3V_AUX power 50 ms before the application of the main power.

Up to four VITA 62-compliant user-defined pins, supported by the onboard FPGA, are also available. These pins can be easily tailored to individual customer’s requirements and applications.

In addition to the system’s primary EMI/EMC power input filter, located in a faraday cage on the chassis front panel, a second stage EMI/RFI filter onboard the P233 further reduces conducted and radiated switching noise on the input lines. Enhanced EMI/RFI shielding provided by the PSU’s heatsink protects the on-board components and the second stage filter. Aitech helps users optimize the design of the primary EMI/RFI filter, once the system’s power requirements are known.

The PSU offers a minimum efficiency of 90% and comes in a conduction-cooled format for both rugged and military applications. Compliant with ANSI/VITA 47-R2007 environmental specifications, the PSU meets the highest operating shock resistance of OS2 (Operational Shock, Level 2 of 40g, 11ms) and the highest vibration level specification V3 (0.1 g2/Hz).