AHF2800 Series
Hybrid - High Reliability
DC/DC Converters
DESCRIPTION
The AHF Series of DC/DC converters feature
single or dual outputs over the full military
temperature range. No derating in output power is
required, making them suitable for use in rugged
military applications. The low profile, small outline
package is ideally suited to the tight board space
requirements of many industrial and aerospace
applications. Designed for nominal 28VDC inputs,
this family of converters will meet the
requirements of MIL-STD-704D. The basic circuit
utilizes a pulse width modulated, feed-forward
topology at a nominal switching frequency of 550
KHz. Input to output isolation is achieved through
the use of transformers in the forward and
feedback circuits.
The proprietary magnetic feedback circuit provides
for an extremely wide bandwidth control loop with
a high phase margin. The closed loop frequency
response of this converter family extends to
approximately 50 kHz, resulting in superior line
and load transient characteristics. This feedback
method is also inherently temperature and
radiation insensitive. This gives the AHF Series an
important advantage over converters that
incorporate opto-couplers in their design.
These converters are manufactured in a facility
certified to MIL-PRF-38534. All processes used to
manufacture these converters have been qualified
to enable Lambda Advanced Analog to deliver
compliant devices. Four screening grades are
available to satisfy a wide range of requirements.
The CH grade converters are fully compliant to
MIL-PRF-38534 class H. The HB grade
converters are processed to full MIL-PRF-38534
screening but do not have class H element
evaluation as required by MIL-PRF-38534. Two
grades are fully tested and operate over the full
military temperature range without derating of
output power. Industrial and commercial grades
are also available. Variations in electrical,
mechanical and screening can be accommodated.
Extensive computer simulation using complex
modeling enables rapid design modification to be
provided. Contact Lambda Advanced Analog with
specific requirements.
FEATURES
a7316 - 40 VDC input range
(28 VDC nominal)
a73Single and dual outputs
a7312 watts output power
a7322.8 W/in
3
power density
a73Low input/output noise
(50 mA/60 mV p-p max. respectively)
a73Indefinite short circuit and overload
protection
a73Wideband control loop for superior
transient characteristics
a73No derating for -55°C to +125°C
operation
a73Constant switching frequency
(550 kHz nominal)