F
EATURES
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–55° to +125°C operation
16 to 40 VDC input
Fully Isolated
Optocoupler feedback
Fixed frequency 550 kHz typical
Topology – Single Ended Flyback
50 V for up to 50 ms transient protection
Inhibit function
Indefinite short circuit protection
Up to 74% efficiency
DC/DC C
ONVERTERS
28 V
OLT
I
NPUT
MGA SERIES
5 WATT
MODELS
VDC O
UTPUT
SINGLE
5
12
15
DUAL
±5
±12
±15
Size (max.): 1.110 x 1.110 x 0.250 inches (28.19 x 28.19 x 6.35 mm)
Shown with “Gull Wing” lead option, also available with straight
leads. See Section B8, case D, for dimensions and options.
Weight:
15 grams maximum.
Screening: Standard, ES, or 883 (Class H). See Section B9 for
screening options, see Section A5 for ordering information.
DESCRIPTION
The MGA Series™ of DC/DC converters delivers 5 watts of output
power from a wide input voltage range of 16 to 40 VDC with up to
74% efficiency. Output models of 5, 12, 15, ±5, ±12 and ±15 VDC
meet a variety of system needs. All units withstand transients of up
to 50 V for up to 50 milliseconds and operate over the full military
temperature range of -55°C to +125°C.
a TTL low voltage (0.8 V or less) to the inhibit terminal (pin 1)
disables the output. Leaving the inhibit terminal unconnected or
connecting the inhibit terminal to an open collector gate enables the
output. The inhibit terminal has an open circuit voltage of 9 to 11 V.
In the inhibit mode the inhibit pin will source a maximum of 4 mA.
See “Inhibit Interface,” Figure 2.
C
ONVERTER
D
ESIGN
The MGA converters incorporate flyback topology with a typical
constant switching frequency of 500 kHz. Isolation between input
and output circuits is provided with a transformer in the forward path
and a temperature compensated optical link in the feedback control
loop. The feed-forward compensation design delivers an audio
rejection of 50 dB, typical, with input ripple as low as 50 mA p-p and
output ripple as low as 100 mV p-p. Output filter examples in Figures
3 and 4 provide suggested solutions for systems where very low
output ripple is required.
Tightly coupled magnetics minimize cross regulation in the MGA
dual output models. Either output can provide up to 80% of the total
available output power, providing the opposite output is carrying at
least 20% of the total output power.
The converter’s short circuit current protection restricts the output
current to approximately 115% of the full load output current.
MIL-STD-461
Use Interpoint’s FMGA-461 EMI filter to pass the CE03 require-
ments of MIL-STD-461C.
S
URFACE
M
OUNT
P
ACKAGE
The MGA DC/DC converters can be surface mounted with pick-and-
place equipment or manually. It is recommended that the case be
attached with flexible epoxy adhesive or silicone which is thermally
conductive (>1 watt /meter/°K).
Internal components are soldered with SN96 (melting temperature
221°C) to prevent damage during reflow. Maximum reflow tempera-
ture for surface mounting the MGA converter is 220°C for a
maximum of 30 seconds. SN60, 62, or 63 are the recommended
types of solder. Hand soldering should not exceed 300°C for 10
seconds per pin.
The hermetically sealed metal cases are available in two different
lead configurations. See Section B8, cases D1 and D2.
I
NHIBIT
F
UNCTION
The MGA converter’s inhibit terminal disables internal switching,
resulting in no output and very low quiescent input current. Applying
B2-81
INTERPOINT [ INTERPOINT CORPORATION COMPANY ]
