description

The MWR Series™ of high frequency DC-DC converters offers

a wide input voltage range of 14 to 50 volts and up to 35 watts

of output power. The units are capable of withstanding short

term transients up to 80 volts for one second. The package

is a hermetically sealed, welded metal case. Flanged and

non-flanged models are available.

MWR Series DC-DC converters are switching regulators that use

continuous flyback conversion topology with a clock frequency

of approximately 300 kHz. MWR Series converters incorporate

two internal converters with one converter phase shifted

approximately 120° from the other to create a dual phase/phase-

shifted operation. Each of the internal converters operates at the

clock frequency. This design provides completely independent

regulation with no cross regulation effect between the main

and auxiliary outputs and no minimum loading required on the

main output. The design minimizes input ripple, greatly reduces

output ripple and improves efficiency. See “Figure 1: MWR Block

Diagram” on page 2.

The MWR converters’ feed-forward compensation system

provides excellent dynamic response and noise rejection. Audio

rejection is typically 40 dB.

The MWR Series converters are provided with internal filtering

capacitors that help reduce the need for external components

in normal operation. Use our FMCE-0528 EMI filter to meet

the requirements of MIL-STD-461C CE03 and CS01 and/or

MIL-STD-461D, E and F CE102 and CS101 levels of conducted

emissions.

MWR 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 the

inhibit pin is pulled below 0.8 volts. 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 8.5 to 12 V.

In the inhibit mode, a maximum of 4 mA must be sunk from the

inhibit pin.

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 270

kHz and 330 kHz. The sync control operates with a duty cycle

between 40% and 60%.

MWR Series converters provide short circuit protection by

restricting the output current to approximately 150% of the

full load output current. The output current is sensed in the

secondary stage to provide highly predictable and accurate

current limiting, and to eliminate foldback characteristics. For

better protection, the current limit function of the main and the

auxiliary sides are linked together. If one output goes to current

limit, the other outputs will be turned off at the same time.

Undervoltage lockout with hysteresis prevents the units from

operating below approximately 12 volts input voltage to keep

system current levels smooth, especially during initialization or

re-start operations.

Features

• Inputvoltagerange14to50V

• Transientprotectionupto80V

foronesecond

• Outputshortcircuitprotection

• -55°Cto+125°Coperation

• Magneticfeedback

• Synchronization

• Inhibitfunction

• Undervoltagelockout

ModeLs

TRIpLE

3.3 V ±12 V

3.3 V ±15 V

5 V ±12 V

5 V ±15 V

Crane Aerospace & Electronics Power Solutions

MWRTripleDC-DCConverters

Crane Aerospace & Electronics

Power Solutions – Interpoint Products

10301 Willows Rd. NE, Redmond, WA 98052

+1 425-882-3100 • power@crane-eg.com

www.craneae.com/interpoint

MWR Rev AD - 2016.05.20

14TO50VOlTInpUT-35WaTT

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