Crane Aerospace & Electronics Power Solutions
SꢀTR Single, Dual and Triple DC-DC Converters
28 VOLT INPUT – 30 WATT
FEATURES
Single, Dual and Triple models
• Operating temperature -55° to +125°C
• Qualified to MIL-PRF-38534 Class H and K
• Radiation hardness assurance (RHA)
to level R 100 krad(Si)
• Input voltage range 16 to 40 VDC
• Transient protection 50 V for 50 ms
• Fully isolated, magnetic feedback
• Fixed high frequency switching, 600 kHz typical
• Trim function or remote sense on single output models
• Inhibit function
ꢀODEꢁS
VDC Output
• Synchronization function
SINGLE
DUAL
±5
TRIPLE
+5 & ±12
+5 & ±15
• Indefinite short circuit protection
3.3
5
• Up to 84% efficiency (up to 73% efficiency triple models)
±12
±15
12
15
DESCRIPTION
The Interpoint™ SMTR Series™ of 28 volt dc-dc converters
offers up to 30 watts of output power from single, dual or
triple output configurations. They operate over the full military
temperature range of -55°C to +125°C with up to 84% efficiency
(up to 73% efficiency triple models). SMTR converters are
packaged in hermetically sealed metal enclosures, making them
ideal for use in military, aerospace and other high reliability
applications.
converter DeSign
The SMTR converters are constant frequency, pulse-width
modulated switching regulators which use a quasi-square wave,
single ended, forward converter design. Tight load regulation is
maintained by using a wide bandwidth magnetic feedback and,
on single output models, through use of remote sense. On dual
output models, the positive output is independently regulated and
the negative output is cross regulated through the use of tightly-
coupled magnetics. The triple output dc-dc converter’s
Screening
design includes individual regulators on the auxiliary outputs
SMTR converters offer screening options to Space Prototype (O), which provide for no cross regulation error when a minimum
Class H, or Class K. Radiation tolerant to Radiation Hardness
Assurance (RHA) levels of “-” (O), “P,” or “R,” per MIL-STD-
38534. Interpoint™ model numbers use an “O” in the RHA
designator position to indicate the “-” (dash) Radiation Hardness
Assurance level of MIL-PRF-38534, which is defined as “no
RHA”. See “Table 11: Element Evaluation” on page 19 and
“Table 12: Environmental Screening and RHA Levels” on page
20 for more information.
300 mA load is maintained on the main (+5 V) output.
SMTR converters have an internal input filter that helps reduce
the need for external components in normal operation. Use our
SFMC EMI input filter to meet the requirements of MIL-STD-
461C’s CE03. For the lowest noise performance, connection
of the case to input common is recommended. The connection
can be hard-wired or AC coupled with a small ceramic bypass
capacitor. Indefinite short circuit protection and overload
protection are provided by a constant current-limit feature. This
protective system senses current in the converter’s secondary
stage and limits it to approximately 140% of the maximum rated
output current.
Crane Aerospace & Electronics
Page 1 of 20
Power Solutions – Interpoint Products
10301 Willows Rd. NE, Redmond, WA 98052
+1.425.882.3100 • power@crane-eg.com
www.craneae.com/interpoint
SMTR Rev AA - 2013.04.18
The information in this document is a derivative of documents cleared by the Department
of Defense (DoD) Office of Security Review (OSR) for public release. OSR case numbers
09-S-1002 dated March 24, 2009 and 12-S-2048 dated May 29, 2012.