www.irf.com 5
AMA28XXD Series
Block Diagram
Application Information
Inhibit Function (Enable)
Connecting the enable input (Pin 5) to input common
(Pin 7) will cause the converter to shut down. It is
recommended that the enable pin be driven by an
open collector device capable of sinking at least 400
µA of current. The open circuit voltage of the inhibit
input is 10 +1.0 VDC.
An optional EMI filter is available (ASF461 or AFH461)
will reduce the input ripple current to levels below the
limits imposed by MIL-STD-461 CE03.
EMI Filter
Thermal Considerations
Irrespective of the fact that the AMA28XXD series
of converters are relatively low power devices and
are designed to provide efficient voltage
conversion, there will be some heat generated
during normal operation. To avoid a continuous
thermal rise that may eventually exceed the
maximum case temperature rating and to maintain
a safe operating environment for the internal
components, these converters should be attached
to a heat conducting surface allowing a continuous
flow of the heat away from the base plate. This
becomes more important when operating in the near
vacuum environment of space which provides no
alternate heat radiating path.
Radiation Specification
Parameter
Condition Min Typ Max Unit
Total Ionizing Dose MIL-STD-883, Method 1019.4
Operating bias applied during exposure
25
—
—
KRads
(Si)
Heavy Ion
(Single event effects)
BNL Dual Van de Graf Generator 60
—
—
MeV
•
cm2
/mg
International Rectifier currently does not have a DSCC certified Radiation Hardness Assurance Program.
Controller
Error
Amplifier
1
2
8
6
7
5
Case
Output
Return
+Output
Enable
Input
Return
+Input
3
-Output
CS
Housekeeping
Supply
