www.irf.com

5

AMR28XXD Series

(28V Input, Dual Output)

Block Diagram

Application Information

Inhibit Function (Enable)

EMI Filter

Device Synchronization

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.

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.

1.

Parameter guaranteed by line and load regulation tests.

2.

Up to 90 percent of full power is available from either output provided the total output does not exceed 30 watts.

3.

Bandwidth guaranteed by design, Tested for 20 Hz to 2 MHz.

4.

5.

3 watt load on output under test. 3 watt to 27 watt load change on other output.

6.

Capacitive load may be any value from 0 to the maximum limit without compromising DC performance. A

capacitive load in excess of the maximum limit will not disturb loop stability but may interfere with the operation

of the load fault detection circuitry, appearing as a short circuit during turn-on.

7.

Parameter shall be tested as part of design characterization and after design or process changes, Parameters

shall be guaranteed to the limit specified in Electrical Specifications.

8.

Load step transition time between 2 and 10 microseconds.

9.

±1% of Vout at

50% load.

10.

Input step transient time between 2 and 10 microseconds.

11.

Turn-on delay time measurement is for either a step application of power at the input or the removal of a ground

signal from the inhibit pin while power is applied to the input.

Notes to Specifications

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

FB

CS

Drive

6

-Output

5

Case