COTS Approach Cuts Cost for Mil-Spec DC-DC Converters

Oct 1, 2006 12:00 PM

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Available in 5-W, 15-W and 35-W ratings, XP Power's MTC series of dc-dc converters is a standard product family developed exclusively for defense and avionics applications. The converters are built using commercial off-the-shelf (COTS) surface-mount components, instead of the usual hybrid assembly. Because of this distinction, the MTC series converters can offer substantial cost savings over traditional, custom military power supplies and are available from stock to reduce system time-to-market.

Unlike some custom military supplies, the MTC series converters are potted but not hermetically sealed. In addition, these devices operate up to a maximum case temperature of 100°C rather than the full 125°C case temperature specified by military hybrids. However, according to the vendor, a large segment of the market for military-grade supplies — perhaps 80% — can accept these compromises on hermeticity and temperature range in exchange for the lower cost and availability of a standard power product. The vendor also notes that no compromise has been made in component selection or construction to make the MTC series adaptable for communications, industrial or transport applications.

The converters meet the MIL-STD 810F specification for temperature, shock, vibration, bump, altitude, salt fog and other key parameters associated with military applications. Suitable for systems with a nominal 28-V input, these units feature an input range of 15.5 V to 40 V, and can operate through transients of 10 V for 10 seconds and up to 50 V for one second, in accordance with MIL-STD 704B-F.

Input immunity with the complementary filter module, designated MTF, meets MIL-STD 1275A/B and MIL-STD 704A. EMI performance meets MIL-STD 461E with the filter installed. Single-output versions are available with output voltages of 3.3 V, 5 V, 12 V, 15 V or 28 V. It includes an inhibit line, the ability to synchronize with an external frequency source, output voltage programmable by resistor or external voltage, thermal warning “battle mode” signal on the 35-W units, overvoltage protection and overcurrent protection.

Both the MTC and MTF are available now. The MTC is priced from $120 each for the 4-W unit to $260 each for the 35-W version. MTFs are $170 each. All prices are based on 100-plus quantities.

For more information, see www.xppower.com.