PD - 94557
ATW28XXD SERIES
ADVANCED ANALOG
HYBRID-HIGH RELIABILITY
DC/DC CONVERTERS
Description
The ATW28XXD Series of DC/DC converters feature
high power density and an extended temperature range
for use in military and industrial applications. Designed
to MIL-STD-704 input requirements, these devices op-
erate with a nominal 28 VDC inputs with 鹵12V and 鹵15V
dual outputs to satisfy a wide range of requirements.
The circuit design incorporates a pulse width modu-
lated push-pull topology operating in the feed-forward
mode at a nominal switching frequency of 270KHz. Input
to output isolation is achieved through the use of trans-
formers in the forward and feedback circuits.
The advanced feedback design provides fast loop re-
sponse for superior line and load transient character-
istics and offers greater reliability and radiation toler-
ance than devices incorporating optical elements in
the feedback circuits.
Three standard temperature grades are offered. Refer
to Part Number section for more severe environments.
Manufactured in a facility fully qualified to MIL-PRF-
38534, these converters are available in four screen-
ing 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 re-
quirements, e.g., element evaluation and Periodic In-
spection (PI) not required. Both grades are tested to
meet the complete group 鈥淎鈥?test specification over the
full military temperature range without output power
deration. Two grades with a more limited screening
are also available for use in less demanding applica-
tions. Variations in electrical, mechanical and screen-
ing can be accommodated. Contact Advanced Analog
for special requirements.
28V Input, Dual Output
ATW
Features
n
18 to 40 VDC Input Range (28 VDC Nominal)
n
鹵
12V and
鹵
15V Outputs Available
n
Indefinite Short Circuit and Overload
Protection
3
n
22.8 W/in Power Density
n
30 W Output Power
n
Fast Loop Response for Superior Transient
Characteristics
n
Operating Temperature Range from -55擄C to
+125擄C Available
n
Popular Industry Standard Pin-Out
n
Resistance Seam Welded Case for Superior
Long Term Hermeticity
n
Efficiencies up to 85%
n
Shutdown from External Signal
n
Full Military Screening
n
200,000 hour MTBF at 85擄C
n
MIL-PRF-38534 Compliant Versions
Available
www.irf.com
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10/24/02
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