HI-REL DC to DC Converters

FEI designs and produces fully radiation hardened proprietary space-qualified hybrids. This Converter-Controller hybrid, the heart of most FEI DC-DC Converters, uses dual switching FETs. For greater power, more than one hybrid may be used in parallel.

Model FE-280A

Small size: 3.5 x 1.56 x 0.6 in
Light Weight 3.5 oz.
Power Density 0.2 W/gm,
5.7 W/oz, 6.7 W/cubic inch

Built-in EMI Filter
Tight Regulation to 1%
Radiation Hardened


Function Description
The new Model FE-280A Series of DC/DC Converters offers up to 20 watts of power in a small aluminum case. Units are available in single, dual or triple outputs. All units include input and output filtering to meet stringent EMI requirements. The converter can offer regulation of better than 1% at end of life, typical 12 year mission.

The units can operate from bus voltages of 20 VDC to 46 VDC over a 35 percent range. The input to output isolation is 1 megohm minimum.

The Model FE-280A series uses a constant frequency pulse width modulated, current mode control switching regulator design with a switching frequency of 250 kHz nominal. Transformer coupling is implemented in the forward power circuit and feedback loop for high isolation and reliability.

All active circuitry is contained in the hybrid. The magnetics and the input-output filters are mounted on a multilayer printed circuit board with the hybrid. All power components are directly coupled to the base plate for low thermal resistance. (Maximum junction temperature at ambient 60 C is 95 C).

The above features are incorporated in our standard designs. Modifications of these units can give unlimited flexibility. Some options that can be incorporated into these designs are:

1. Synchronized switching rate; used to control interference in critical applications.
2. Bus inputs available (20V-60V).
3. Reverse Polarity protection.
4. Commands for ON and OFF.
5. Input preregulator for improved ripple rejection.

Dedication to Quality
FEI's exceptional reliability is due to tight control of quality. This is facilitated by a high degree of vertical integration, which allows us to take full responsibility at every step.

The thin and thick film hybrids we design and produce (in Class 10,000 cleanrooms) meet levels S and B of MIL-M-38510 and have been certified by prime contractors.

Our certified instuctors in turn train and certify our operators to MIL-STD-2000. Our soldering meets WS-6536 (USN), MIL-S-45743E (USAF) and NHB 5300.4 (341) (NASA).

The FEI management system focuses on quality and exceeds the requirements of MIL-Q-9858A, monitored by DCAS.

PC board design and fabrication is QPL-listed for MIL-P-55110D types GF, GY, GR and GI, and has been qualified in space. We are conducting a continuing TQM initiative to produce the highest quality product.

Reliability by Design
This enviable record testifies to our dedication to reliable design and process control. Wherever possible, proven sub-assemblies are used in our custom designs. These include our own hybrids, qualified for space. Semi-conductors and other parts are derated by at least 2:1 electrically and mechanically, and conservatively rated for thermal and radiation stress.

Physical Configuration

Space Heritage - DC/DC Converters
FEI Has a long history of producing space-qualified DC/DC Converters. A partial list follows:
Power Converter Units (PCUs)
Watts Outputs Input Voltage Redundancy Special
4 3 27 to 29 VDC    
15 6 22 to 34 VDC YES  
20 3 22 to 34 VDC   YES
22 6 22 to 34 VDC YES YES
25 3 22 to 34 VDC YES YES
30 6 22 to 34 VDC   YES
30 3 19 to 36 VDC YES  
  1500 & 3000 VDC 24 to 34 VDC   YES
100 18 22 to 34 VDC   YES
170 6   YES  

Note: FEI builds DC-DC Converters to order.