1

MSM SERIES

5 WATT

• –55°C to +125°C operation

• 16 to 40 VDC input

• Surface mountable

• Will withstand solder reflow

• Transient protection up to 80V/120 ms,

meets MIL-STD-704A requirements

• Inhibit function

• Fully isolated

• Ultra-wide bandwidth magnetic feedback

• Up to 82% efficiency

• Indefinite short circuit protection

• Undervoltage shutdown below 10 Vin

DESCRIPTION

The MSM Series™ of DC/DC converters delivers up to 5 watts in a

surface mountable package. The use of commercially available

discrete components, printed wiring board construction, and surface

mount technology keep costs low. Mature design technology and

severe derating maintain high-reliability, providing full power opera-

tion over the full military temperature range of –55 to +125°C.

Output voltages of 3.3, 5, 5.2, 12, 15, ±12, or ±15 operate from an

input range of 16 to 40 VDC. Operation below 16 volts is possible at

reduced power while still maintaining output regulation. The

converters are rated for input transients up to 80 V for up to 120

milliseconds which meets the requirements for MIL-STD-704A.

The converters incorporate a flyback topology with a constant

frequency to minimize EMI and noise. The pulse-width-modulator is

constructed of discrete devices to allow to the use of mature tech-

nologies and assure operation over the full temperature range. A

proprietary magnetic isolator, designed with feed-forward and load

correction, provides nearly instantaneous output control for good

output regulation.

MSM Series converters provide a TTL open collector-compatible

inhibit feature that can be used to disable internal switching and

inhibit the unit’s output. Inhibiting in this manner results in low

standby current, and no generation of switching noise.

The converter is inhibited when the TTL compatible low (

≤0.8 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 0.5 mA must be sunk from the inhibit pin.

Undervoltage lockout prevents the MSM Series converters from

operating below approximately 10 VDC input. This circuitry can

prevent system shutdown problems in starting “constant power”

devices at low input voltages. All models include a soft-start function

to prevent large current draw and minimize overshoot under all load

and line conditions. The MSM Series of converters also provide

short circuit and overload protection. Short circuit internal dissipation

is lower than the internal dissipation which occurs during full load

conditions.

The MSM Series of DC/DC converters can be surface mounted or

hand-soldered. Maximum reflow temperature for surface mounting

the MSM converter is 230°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.

Size (max.):

2.01 x 2.01 x 0.312 inches (51.1 x 51.1 x 7.9 mm)

Weight:

20 grams maximum

MODELS

SINGLES

3.3

5

12

15

DUALS

±12

±15