鈥?/div>
鈥?5擄 to +125擄C operation
16 to 40 VDC input
Fully isolated
Magnetic feedback
Fixed frequency 600 kHz typical
Topology 鈥?Single Ended Forward
50 V for up to 50 ms transient protection
Inhibit and synchronization functions
Indefinite short circuit protection
Up to 30 watts output power
Trim and remote sense on single
output models
鈥?Up to 84% efficiency
DC/DC C
ONVERTERS
28 V
OLT
I
NPUT
MTR SERIES
30 WATT
MODELS
VDC O
UTPUT
SINGLE
DUAL
TRIPLE
3.3
鹵5
+5 &
5
鹵12
鹵12
12
鹵15
+5 &
15
鹵15
18
Size (max): Non-flanged: Single and dual output models, case H2 (H4 for MTR Dual with standard or ES screening, ht 0.417", 10.59 mm)
2.125 x 1.125 x 0.400 inches (53.98 x 28.58 x 10.16 mm)
Triple output models, case F1, 1.950 x 1.350 x 0.405 inches (49.53 x 34.29 x 10.29 mm)
Flanged:
Single and dual output models, case K3 (or K5 for MTR Dual with standard or ES screening, ht. 0.417", 10.59 mm)
2.910 x 1.125 x 0.400 inches (73.91 x 28.58 x 10.16 mm)
Triple output models, case J1, 2.720 x 1.350 x 0.405 inches (69.09 x 34.29 x 10.29 mm)
Single and dual non-flanged 50 grams max., flanged 52 grams max.
Triple non-flanged 58 grams max., flanged 62 grams max.
Screening: Standard, ES, or 883 (Class H).
Weight:
DESCRIPTION
The MTR Series鈩?of 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 with up to 84% effi-
ciency. MTR converters are packaged in hermetically sealed metal
cases, making them ideal for use in military, aerospace and other
high reliability applications.
S
YNCHRONIZATION
Synchronizing the converter with the system clock allows the
designer to confine switching noise to clock transitions, minimizing
interference and reducing the need for filtering. In sync mode, the
converter will run at any frequency between 500 kHz and 675 kHz.
The sync control operates with a quasi-TTL signal at any duty cycle
between 40% and 60%. The sync pin must be connected to input
common pin when not in use.
C
ONVERTER
D
ESIGN
The MTR 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 via
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 and shunt
regulators. The MTR Series triple output DC/DC converter鈥檚 design
includes individual regulators on the auxiliary outputs which provide
for no cross regulation error when a minimum 500 mA load is main-
tained on the main (+5) output.
Indefinite short circuit protection and overload protection are
provided by a constant current-limit feature. This protective system
senses current in the converter鈥檚 secondary stage and limits it to
approximately 115% of the maximum rated output current.
MTR converters are provided with internal filtering capacitors that
help reduce the need for external components in normal operation.
For systems that require compliance with MIL-STD-461C鈥檚 CE03
standard, Interpoint offers filter/transient suppression modules
(including the FMC-461, FMD-461 and FM-704A series filters) which
will result in compliance. Contact your Interpoint representative for
further details.
W
IDE
V
OLTAGE
R
ANGE
MTR converters are designed to provide full power operation over a
full 16 to 40 VDC voltage range. Operation below 16 volts, including
MIL-STD-704E emergency power conditions is possible with
derated power. Refer to the low line dropout graph (Figure 22) for
details.
I
MPROVED
D
YNAMIC
R
ESPONSE
The MTR Series feed-forward compensation system provides excel-
lent dynamic response and noise rejection. Audio rejection is typi-
cally 50 dB. The minimum to maximum step line transient response
is typically less than 4%.
I
NHIBIT
F
UNCTION
MTR converters provide an inhibit terminal that can be used to
disable internal switching, resulting in no output and very low
quiescent input current. The converter is inhibited when a TTL
compatible low (鈮?.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 V. In the inhibit mode, a maximum of 8 mA must be sunk
from the inhibit pin.
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