PD - 94435
AFL270XXS SERIES
270V Input, Single Output
ADVANCED ANALOG
HIGH RELIABILITY
HYBRID DC/DC CONERTERS
Description
The AFL Series of DC/DC converters feature high power
density with no derating over the full military tempera-
ture 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, multiple
converters can be operated in parallel. The internal cur-
rent sharing circuits assure equal current distribution
among the paralleled converters. This series incorpo-
rates Advanced Analog’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 con-
verters 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.
AFL
Features
n 160 To 400 Volt Input Range
n 5, 6, 9, 12, 15 and 28 Volt Outputs Available
n High Power Density - up to 84 W /in
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n Up To 120 Watt Output Power
n Parallel Operation with Stress and Current
Sharing
n Low Profile (0.380") Seam Welded Package
n Ceramic Feedthru Copper Core Pins
n High Efficiency - to 87%
n Full Military Temperature Range
n Continuous Short Circuit and Overload
Protection
n Remote Sensing Terminals
n Primary and Secondary Referenced
Inhibit Functions
n Line Rejection > 60 dB - DC to 50KHz
n External Synchronization Port
n Fault Tolerant Design
These converters are hermetically packaged in two en-
closure variations, utilizing copper core pins to mini-
mize resistive DC losses. Three lead styles are avail-
able, each fabricated with Advanced Analog’s rugged
ceramic lead-to-package seal assuring long term
hermeticity in the most harsh environments.
n Dual Output Versions Available
n Standard Military Drawings Available
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 fully processed and
screened to the class H requirement, but does not have
material element evaluated to the class H requirement.
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 available for use in less
damanding applications. Variations in electrical,
mechanical and screening can be accommo-
dated. Contact Advanced Analog for special re-
quirements.
www.irf.com
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04/23/02