AHV28

The AHV Series of DC/DC converters are designed to replace the AHE/ATO family of converters in applications requiring compliance to MIL-STD-704A through E, in particular the input surge requirement of 80 volts specified to withstand transient input voltage of 80 volts.No input voltage or output power derating is necessary over the full military temperature range.These AHV Series  converters are packaged in an extremely rugged,low profile package that meets all requirements of MIL-STD-883 and MIL-PRF-38534. Parallel seam weld sealing and the use of ceramic pin feedthru seals assure long term hermeticity after exposure to extended temperature cycling.

The basic circuit of AHV Series  is a push-pull forward topology using power MOSFET switches. The nominal switching frequency is 500KHz. A unique current injection circuit assures current balancing in the power switches. All AHV series converters use a single stage LC input filter to attenuate input ripple current. A low power 11.5volt series regulator provides power to an epitaxial CMOS custom pulse width modulator integrated circuit. This single integrated circuit provides all PWM primary circuit functions. Power is transferred from primary to secondary through a ferrite core power transformer. An error voltage signal is generated by comparing a highly stable reference voltage with the converter output voltage and drives the PWM through a unique wideband magnetic feedback circuit. This proprietary feedback circuit provides an extremely wide bandwidth, high gain control loop, with high phase margin.

The feedback control loop gain of AHV Series  is insensitive to temperature, radiation,aging, and variations in manufacturing. The transfer function of the feedback circuit is a function of the feedback transformer turns ratio which cannot change when subjected to environmental extremes.The CH grade is fully compliant to the requirements of MIL-PRF-38534 for class H. The HB grade is processed and screened to the class H requirement, but may not necessarily meet all of the other MIL-PRF-38534 requirements, e.g., element evaluation and Periodic Inspection (P.I.) not required. Both grades are tested to meet the complete group "A" test specification over the full military temperature range without output power deration. Two grades with more limited screening are also available for use in less demanding applications. Variations in electrical, mechanical and screening can be accommodated. Contact Advanced Analog for special requirements.Manufactured in a facility fully qualified to MIL-PRF-38534, these AHV Series  converters are available in four screening grades to satisfy a wide range of requirements.