Crane Aerospace & Electronics Power Solutions
SMSA Single and Dual DC-DC Converters
28 Volt input – 5 Watt
Features
small size, 1.16 in
2
(7.5 cm
2
)
• 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
• Fully isolated
• Transient protection 50 V for 50 ms
• Fixed high frequency switching
• Inhibit function
• Indefinite short circuit protection
MODELS
vDc o
utput
• Operating temperature -55° to +125°C
SIngLE
3.3
5
5.2
12
15
DuAL
±5
±12
±15
• High power density, 74% efficiency
description
The SMSA Series™ of high frequency, space qualified, dc-dc
converters provide up to 5 watts output power over the full
military temperature range of -55°C to +125°C with up to 74%
efficiency. Thick-film hybrid techniques provide military/aerospace
reliability levels and optimum miniaturization. The hermetically
sealed case is 1.075 by 1.075 inches with a height of 0.270
inches. Power density for the SMSA Series converters is 16 watts
per cubic inch. The SMSA Series’ small size, light weight and
hermetically sealed metal packages make them ideal for use in
space, military, aerospace and other high reliability applications.
Predictable current limit is accomplished by direct monitoring
of the output load current, which results in a constant current
output above the overload point. Internal input and output filters
eliminate the need for external capacitors.
W
iDe
v
oltage
r
ange
The SMSA converters are designed to provide full power
operation over the full 16 to 40 VDC voltage range. An
undervoltage lockout feature keeps the converter shutdown
below approximately 13 VDC to ensure smooth initialization.
S
creening
SMSA converters offer the following screening options: Space
Prototype (O), 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 10: Environmental Screening and RHA
Levels” on page 15 for more information.
D
ynamic
r
eSponSe
The SMSA feed-forward compensation system provides excellent
dynamic response and noise rejection. Audio rejection is typically
50 dB (“Figure 15” on page 11). The minimum to maximum
step line transient response is typically less than 1% (“Figure 10”
on page 10 and “Figure 19” on page 11).
i
nhibit
F
unction
c
onverter
D
eSign
The SMSA converters are switching regulators that use a flyback
converter design with a constant switching frequency of 500 kHz.
They are regulated, isolated units using a pulse width modulated
topology. Isolation between input and output circuits is provided
with a transformer in the forward power loop and an optical link in
the feedback control loop. Excellent input line transient response
and audio rejection is achieved by an advanced feed-forward
compensation technique.
On dual output models negative output regulation is maintained
by tightly coupled magnetics.
SMSA converters provide an inhibit feature that can be used to
disable internal switching and inhibit the unit’s output. Inhibiting in
this manner results in low standby current, and no generation of
switching noise.
The converter is inhibited when an active low (≤0.8 V) is applied
to the inhibit pin. The unit is enabled when the pin, which is
internally connected to a pull-up resistor, is left unconnected or
is connected to an open collector gate. The open circuit output
voltage associated with the inhibit pin is 9 to 11 VDC. In the
inhibit mode, a maximum of 4 mA must be sunk from the inhibit
pin at 28 VDC input.
Crane Aerospace & Electronics
Power Solutions – Interpoint Products
10301 Willows Rd. NE, Redmond, WA 98052
+1.425.882.3100 • power@crane-eg.com
www.craneae.com/interpoint
The information in this document has been cleared by the Department of
Defense (DoD) Office of Security Review (OSR) for public release. OSR case
number 13-S-2440 dated July 30, 2013.
SMSA Rev ABr - 2014.05.07
Page 1 of 15
Crane Aerospace & Electronics Power Solutions
SMSA Single and Dual DC-DC Converters
28 Volt input – 5 Watt
model numbering key
Base Model
SMSA
28 05 S / K R
S
tandard
M
icrocircuit
d
rawing
(SMd)
5962R0621001KXC
5962R9309202KXC
5962R9309302KXC
5962R9309402KXC
5962R0052202KXC
5962R9308902KXC
5962R9309002KXC
smd numbers
SMSa S
iMilar
P
art
Number of Outputs
(S = single, D = dual)
Environmental Screening
Voltage In (28V)
Output Voltage
SMSA283R3/KR
SMSA2805S/KR
SMSA2812S/KR
SMSA2815S/KR
SMSA2805D/KR
SMSA2812D/KR
SMSA2815D/KR
Radiation Hardness
Assurance (RHA)
F
igure
6: m
oDel
n
umbering
k
ey
The SMD number shown is for Class K screening
and Radiation Hardness Assurance (RHA) level R.
See the SMD for the numbers for other screening
and radiation levels. For exact specifications for
an SMD product, refer to the SMD drawing. SMDs
can be downloaded from:
http://www.landandmaritime.dla.mil/programs/smcr
t
able
3: SmD n
umber
c
roSS
r
eFerence
o
n
the lineS below
,
enter one Selection froM each category to deterMine the Model nuMber
.
model number options
category
base model and
input Voltage
output Voltage
1
3R3, 05, 5R2, 12, 15
number of
outputs
2
S
D
screening
3
O
H
K
rHa
4
O
P
R
options
Fill in For model #
SMSA28
05, 12, 15
_____
SMSA28
__________
/
_______
notes:
1. notes: An R indicates a decimal point. 3R3 is 3.3 volts out. The values of 3.3 and 5.2 are only available in single output models.
2. number of Outputs: S is a single output and D is a dual output.
3. Screening: A screening level of O is a Space Prototype and is only used with RHA O. See “Table 9: Element Evaluation” on page 14 and “Table 10: Environmental
Screening and RHA Levels” on page 15 for more information.
4. RHA: 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.” RHA O is only available with Screening level O. See “Table 10: Environmental Screening and RHA Levels” on page 15 for more information.
t
able
4: m
oDel
n
umber
o
ptionS
www.interpoint.com
SMSA Rev ABr - 2014.05.07
Page 5 of 15