MODELS

B2-81

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.

SINGLE

5

12

15

DUAL

±5

±12

±15

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.

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.

The MGA converter’s inhibit terminal disables internal switching,

resulting in no output and very low quiescent input current. Applying

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.

MIL-STD-461

Use Interpoint’s FMGA-461 EMI filter to pass the CE03 require-

ments of MIL-STD-461C.

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.

MGA SERIES

5 WATT

• –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