
Operating COnditiOns and CharaCteristiCs
Input Voltage range
19 to 56 VDC continuous
80 V for 120 ms transient
Output power
Up to 35 watts depending on model
Lead soldering temperature (10 sec per pin)
300°C
storage temperature range (case)
-65°C to +150°C
case Operating temperature (tc)
-55°C to +125°C full power
-55°C to +135°C absolute
Derating Output power/current
Linearly from 100% at 125°C to 0% at 135°C
power Dissipation (pd)
20to31W
Output Voltage temperature coefficient
100 ppm/°C max
current Limit
125% of full load typical
Isolation at 25°c
100 megohm minimum at 500 V
audio rejection
50 dB typical
conversion Frequency
300 kHz typ 270 kHz min, 330 kHz max
radiation (will operate through)
1x10
12 neutrons/cm2 neutron or proton fluence
Radiation dose rate 10
11 rad(Si) /sec
Total dose up to 300 kRad(Si)
SEE - LET to 80 MeV cm2/mg
meChaniCal and envirOnmental
size (maximum)
2.705 x 2.205 x 0.400 inches (68.71 x 56.01 x 10.16 mm)
See case S for dimensions.
Weight (maximum)
100 grams maximum
screening
Space Prototype, Class H, or Class K are radiation tolerant
to Radiation Hardness Assurance (RHA) levels of “-” (O), “P”,
“R”, or “F” per MIL-PRF-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 Screening Tables 1, 2 and 3 for more information. Available
configurations: OO, HP, HR, KP, KR, KF
synC and inhibit
sync
Input frequency 270-330 kHz
Duty cycle 20% min, 80% max
2.5 V p-p minimum amplitude
10 V p-p maximum amplitude
Sync circuit is floating and isolated
If sync is used at lower end of the range, full load
operation is not guaranteed.
Inhibit
Converter disabled (active low)
InH referenced to input common
Active low, pulled to 0.4 V or lower
Inhibit pin current
< 2 mA
Converter enabled (active high)
Active high >2.4 V
not to exceed 10 V
Open pin voltage 5 to 6 V
Crane Aerospace & Electronics Power Solutions
www.craneae.com/interpoint
Page 3 of 22
sMrt28 single, Dual and triple space Dc/Dc converters
28 VOLt Input – 35 Watt – space quaLIFIeD
SMRT28 Rev F - 2011.01.24