Harsh-environment, COTS DC/DC converters extended with 85-W models

The HQA series of isolated DC/DC converters, rated at 85 W, are qualified with methods consistent with MIL-STD-883 and MIL-STD-202, making it suitable for use in COTS and harsh-environment industrial equipment. Initially available with 12-, 24-, and 28-V outputs, the encapsulated quarter bricks accept a wide-range DC input from 9 to 40 V, withstanding a 50-V surge for 10 seconds.

With typical efficiencies of up to 90%, internal heating is minimized, allowing the HQA85 converters to operate in high ambient temperatures of up to 115^° C and a minimum of –40^° C. No optocouplers are used in the design for enhanced reliability at high temperatures, and the switching frequency is fixed at 270 kHz for simplified noise filtering.

The converter pinout follows the industry standard five-pin quarter-brick footprint featuring negative logic remote on/off and +/– remote sense. Two package styles are offered; a flanged type measuring 2.39 x 2.2 x 0.5 in. and a non-flanged version measuring 2.39 x 1.54 x 0.5 in. Input-to-output and input-to-baseplate isolation is 2,250 Vdc, and the converters are safety-certified to UL/CSA/EN 60950-1, with the CE marking in accordance with the LV Directive and RoHS Directives. Applications include COTs, vehicle, airborne, communications, and harsh industrial use.