F
EATURES
• EMI input filter, up to
50 dB attenuation
• –55° to +125°C operation
• High frequency output filter
• 17 to 40 VDC input
• Fully isolated, magnetic feedback
• 600 kHz typical–Single Ended Forward
• Inhibit and synchronization functions
• Indefinite short circuit protection
• Trim and remote sense on singles
• Up to 83% efficiency
• Up to 50V for 50 ms transient
protection
EMI F
ILTERED
DC/DC C
ONVERTERS
28 V
OLT
I
NPUT
FMTR SERIES
30 WATT
MODELS
VDC O
UTPUT
SINGLE
DUAL
3.3
±5
5
±12
12
±15
15
Size (max): 3.005 x 1.505 x 0.400 inches (76.33 x 38.23 x 10.16 mm)
Weight:
100 grams maximum
Screening: Standard or ES, see the Environmental Screening table
DESCRIPTION
The FMTR Series™ of DC/DC converters offers up to 30 watts of
output power from single or dual output configurations. They
operate over the full military temperature range with up to 83% effi-
ciency. FMTR converters are packaged in hermetically sealed metal
cases, making them ideal for use in military, aerospace and other
high reliability applications.
B
UILT
-
IN
F
ILTERS
The built-in input and output filters reduce layout issues and
conserve board space. The 2.7 amp EMI input filter meets MIL-STD-
461C, CE03 and allows filtering of additional converters through the
filter output pins. The output filter reduces high frequency common
and differential mode noise. It allows a higher bandwidth ripple
voltage measurement and eliminates the need for external output
decoupling capacitors. Both input and output filters reduce radiated
emissions providing quieter operation than conventional DC/DC
converters.
C
ONVERTER
D
ESIGN
The FMTR converters are constant frequency, pulse-width mod-
ulated switching regulators which use a quasi-square wave, single
ended, forward converter design. Tight load regulation is maintained
via wide bandwidth magnetic feedback and, on single output
models, through use of remote sense.
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 115% of the maximum rated output current.
W
ARNING
: R
EQUIRED
D
AMPING
N
ETWORK
To prevent damage to the internal circuitry an external capacitor and
resistor are required across the filter outputs (pins 3 and 4) as
shown in Figure 1. This applies to both single and dual output
models. The recommended capacitor type is wet tantalum, MIL-C-
39006.
+Vin
EMI Input Filter 2.7 A max.
28 Vin 8 +
+
4 Filter Output
Required
damping
220
µF
network
2.2
Ω
3 Filter Output Rtn
11 Positive
Output
Additional
DC/DC
Converters
Rtn
Inhibit
~
Input Common 7 –
Inhibit 5
+ Vin
–
Inh
Sync 1
Sync
Inhibit/Sync 2
Return
Sync
Rtn
+
Vout
–
High Frequency
Output Filter
–
DC/DC Converter
10 Output
Common
F
IGURE
1: FMTR T
YPICAL
I
NPUT
I
NTERFACE
A
PPLIES TO
S
INGLES AND
D
UALS
(S
HOWN WITH
S
INGLE
O
UTPUT
)
1
INTERPOINT [ INTERPOINT CORPORATION COMPANY ]
