04/16/09

www.irf.com

1

HIGH RELIABILITY

HYBRID DC/DC CONVERTERS

AHP28XXD SERIES

The AHP Series of DC/DC converters feature high power

density with no derating over the full military temperature

range. This series is offered as part of a complete family

of converters providing single and dual output voltages

and operating from nominal +28 or +270 volt inputs with

output power ranging from 80 to 120 watts. For

applications requiring higher output power, individual

converters can be operated in parallel. The internal

current sharing circuits assure equal current distribution

among the paralleled converters. This series incorporates

International Rectifier’s proprietary magnetic pulse

feedback technology providing optimum dynamic line

and load regulation response. This feedback system

samples the output voltage at the pulse width modulator

fixed clock frequency, nominally 550 KHz. Multiple

converters can be synchronized to a system clock in the

500 KHz to 700 KHz range or to the synchronization

output of one converter. Undervoltage lockout, primary

and secondary referenced inhibit, soft-start and load

fault protection are provided on all models. Also included

is input over-voltage protection, a new protection feature

unique to the AHP.

These converters are hermetically packaged in two

enclosure variations, utilizing copper core pins to

minimize resistive DC losses. Three lead styles are

available, each fabricated with International Rectifier’s

rugged ceramic lead-to-package seal assuring long term

hermeticity in the most harsh environments.

Description

n 16 To 40 Volt Input Range

n High Power Density - up to 70 W / in3

n Up To 100 Watt Output Power

n Parallel Operation with Stress and Current Sharing

n Input Over-Voltage Protection

n High Efficiency - to 85%

n Continuous Short Circuit and Overload

Protection

n External Synchronization Port

n Remote Sensing Terminals

n Primary and Secondary Referenced

Inhibit Functions

n Line Rejection > 40 dB - DC to 50KHz

n Fault Tolerant Design

n Full Military Temperature Range

n Ceramic Feedthru Copper Core Pins

n Low Profile (0.380") Seam Welded Package

n Single Output Versions Available

Features

28V Input, Dual Output

Manufactured in a facility fully qualified to MIL-PRF-

38534, these converters are available in four screening

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 may not

necessarily meet all of the other MIL-PRF-38534

requirements, e.g., element evaluation and Periodic

Inspection (P.I.) not required. Both grades are tested to

meet the complete group “A” test specification over the

full military temperature range without output

power deration. Two grades with more limited

screening are also avail-able for use in less

demanding applications. Variations in electrical,

mechanical and screening can be accommodated.

Contact IR Santa Clara for special requirements.

AHP

PD-97389