PD - 94551
ATR28XXT SERIES
ADVANCED ANALOG
HYBRID-HIGH RELIABILITY
DC/DC CONVERTERS
Description
The ATR28XXT Series of DC/DC converters provide
30 watts of output power over the full military tempera-
ture range with no derating. These devices are pin
compatible with the Advanced Analog ATO series con-
verters but offer twice the maximum output power in a
lower profile package. A custom CMOS ASIC pulse
width modulator operating at a nominal switching fre-
quency of 550KHz combined with a unique magnetic
feedback reduces circuit complexity for enhanced reli-
ability. These converters provide 500 volt input to out-
put isolation and operate in highly efficient single for-
ward mode.
The advanced feedback design and high operating fre-
quency provide an extremely wide bandwidth control
loop with high gain and phase margin. This results in
fast dynamic line and load response as well as supe-
rior audio rejection. The control loop is compensated
to provide optimum performance over the full military
temperature range and over the 16 to 40 volt input
voltage range.
These converters are protected against both continu-
ous output short circuits and output overload. Either
load fault condition will result in operating in a low power
dissipation foldback mode. The converters will shut
down for approximately 15 milliseconds, then attempt
to restart. This cycle will continue indefinitely unless
the load fault is corrected. Recovery to normal opera-
tion is automatic upon removal of the load fault.
Manufactured in a facility full qualified to MIL-PRF-
38534, these converters are available in four screen-
ing grades to satisfy a wide range of requirements. 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 element
evaluation and Periodic Inspections (PI) are not re-
quired. Both grades are tested to meet the complete
group 鈥淎鈥?test specification over the full military tem-
perature range without output power deration.
28V Input, Triple Output
ATR
Features
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30 Watt Output Power
Flexible Output Loading
-55擄C to +125擄C Operation
Pin Compatible with ATO
0.410鈥?Maximum Height
16 to 40 VDC Input Range
500 Volt Input to Output Isolation
High Audio Rejection
MIL-STD-704 Compatible
Load Fault Protection - Short Circuit and
Overload
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TTL level Compatible Synchronization
Two grades with more limited screening are also
available for use in less demanding applications.
Variations in electrical, mechanical and screen-
ing can be limited accomodated. Contact
Advanced Analog with specific requirements.
www.irf.com
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10/08/02
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