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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

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