PD-94583A
AHV28XX SERIES
28V Input, Single, Dual and Triple Output
HYBRID-HIGH RELIABILITY
DC/DC CONVERTER
Description
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 80V specified to
withstand transient input voltage of 80V. No input voltage
or output power derating is necessary over the full military
temperature range.
AHV
These 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 feed thru seals assure long
term hermeticity after exposure to extended temperature
cycling.
Features
n 80V Transient Input (100 msec max.)
n 50V DC Input (Continous)
n 16V to 40V DC Input Range
n Single, Dual and Triple Outputs
n 15W Output Power
The basic circuit 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 11.5V 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 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.
(No Temperature Derating)
n Low Input / Output Noise
n Full Military Temperature Range
n Wideband PWM Control Loop
n Magnetic Feedback
n Low Profile Hermetic Package (0.405”)
n Short Circuit and Overload Protection
n Constant Switching Frequency (500KHz)
n True Hermetic Package (Parallel Seam
Welded, Ceramic Pin Feedthru)
n Standard Microcircuit Drawings Available
Manufactured in a facility fully qualified to MIL-PRF-38534,
these converters are fabricated utilizing DSCC qualified
processes. For available screening options, refer to device
screening table in the data sheet. Variations in electrical,
mechanical and screening can be accommodated.
Contact IR Santa Clara for special requirements.
www.irf.com
1
12/13/06