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5

AMR28XXS Series

Block Diagram

Application Information

Inhibit Function (Enable)

EMI Filter

Device Synchronization

Connecting the inhibit input to input common will

cause the converter to shut down. It is recommended

that the inhibit 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 V

An optional EMI filter is available (AFH461) that will

reduce the input ripple current to levels below the

limits imposed by MIL-STD-461 CE03.

When multiple DC/DC converters are utilized in a

single system, significant low frequency noise may

be generated due to a small difference in the

switching frequency of the converters (beat

frequency noise). Because of the low frequency

nature of this noise (typically less than 10 KHz), it is

difficult to filter out and may interfere with proper

operation of sensitive systems (communication,

radar or telemetry). International Rectifier provides

synchronization of multiple AMR type converters to

match switching frequency of the converter to the

frequency of the system clock, thus eliminating this

type of noise.

MTBF vs Case Temperature for AMR2803R3S

0.00E+00

2.00E+05

4.00E+05

6.00E+05

8.00E+05

1.00E+06

1.20E+06

1.40E+06

1.60E+06

0

20

40

60

80

100

120

Case Temperature, deg C

8

7

+Output

Output

Return

Pulse Width

Modulator

Primary

Housekeeping

Supply

EMI

Filter

Under-Voltage

Detector

1

3

10

2

+Input

Enable

Sync

Input

Input

Return

Error

Amp &

Ref

9

6

+Sense

-Sense

FB

CS

Drive