AHF28XX_10 Datasheet, PDF (1/19 Pages) International Rectifier – HYBRID-HIGH RELIABILITY DC-DC CONVERTER

PD-94541D
HYBRID-HIGH RELIABILITY
DC-DC CONVERTER
AHF28XX SERIES
28V Input, Single and Dual Output
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 550KHz. 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 50KHz,
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.
AHF
Features
n 16V to 40VDC Input Range (28 VDC Nominal)
n Single and Dual Outputs
n 12W Output Power
n 22.8W/in3 Power Density
n Low Input / Output Noise
(50mA/60mVp-p max. respectively)
n Indefinite Short Circuit and Overload Protection
n Wideband Control Loop for Superior Transient
Characterstics
n No derating for -55°C to +125°C Operation
n Constant Switching Frequency (550KHz Nominal)
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 are electrical, mechanical and screening
can be accommodated.
Extensive computer simulation using complex modeling
enables rapid design modification to be provided.
Contact IR San Jose with specific requirements.
www.irf.com
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03/09/10