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📚 Our Guide Series to Military Power Supplies and MIL-STD Standards

This article is part of our guide series covering the design and selection of power supplies and DC-DC converters for military and aerospace systems.

⭐ Main Guide:

Military Power Supplies and DC-DC Converters – A Guide to MIL-STD Standards

📖 Additional Guides in the Series:

MIL-STD-1275 – Power Supplies and DC-DC Converters for Military Vehicles

MIL-STD-704 – Power Supplies for Military and Aerospace Systems

MIL-STD-461 for Military Power Supplies – EMI, EMC and CS101

MIL-STD-810 – Vibration, Shock and Environmental Conditions in Military Power Supplies

MIL-STD-1275 vs. MIL-STD-704 – What’s the Difference and How Do You Choose the Right Power Supply?

Military DC-DC Converters with Built-In EMI Filtering and Input Protection

Each guide focuses on a different aspect of the power system. Together, they provide a broader understanding of the electrical requirements, EMI/EMC requirements, environmental conditions, and integration considerations involved in selecting a power solution for military and aerospace applications.

Military DC-DC Converters with Built-In EMI Filtering and Input Protection

In a military system, selecting a DC-DC converter involves much more than input voltage, output voltage, and power.

A converter installed in a military vehicle, aircraft, or military electronic system must operate in a power environment that is far from ideal. It may be exposed to voltage variations, transients, surges, and electromagnetic interference. At the same time, the system may need to meet EMI/EMC requirements and withstand demanding mechanical and thermal conditions.

As a result, what initially appears to be a simple requirement for a DC-DC converter can quickly become a complete power system consisting of:

  • DC-DC converter
  • Input protection circuitry
  • Transient and surge protection
  • EMI filtering
  • Additional filtering and protection components
  • Thermal management
  • Wiring and connectors
  • In some cases, an additional PCB used to integrate all components into a single system

Each of these elements takes up space, adds weight, increases the component count, and requires additional design, integration, and testing effort.

There is another approach:

Integrate power conversion, EMI filtering, and input protection into a single compact Power Conversion solution tailored to the application.

This approach is particularly relevant for systems with requirements related to MIL-STD-1275, MIL-STD-704, MIL-STD-461, and MIL-STD-810, especially when size, weight, efficiency, and ease of integration are critical system requirements.

In this article, we will explain how these different requirements come together, the difference between an architecture based on multiple separate components and an integrated solution, and how the military power chain can be designed as a single unit rather than a collection of separate solutions.

A DC-DC Converter Is Only One Part of the Power Chain

When an engineer looks for a DC-DC converter, the starting point is usually straightforward:

What is the input voltage?

What is the required output voltage?

How much power is required?

Is isolation required?

What efficiency is required?

These are important questions, but in a military system they are not enough.

For example, a military vehicle may use a 28VDC power system, but 28V is only the nominal voltage. The voltage actually reaching the equipment input is not necessarily a stable 28V, and the system may be exposed to various voltage events.

Similarly, in an airborne system, a power supply cannot be selected based solely on the platform’s nominal voltage.

In addition, the power supply itself is a switching power conversion system. It can therefore both generate interference and be affected by interference entering through the power lines.

In practice, the power chain may therefore look like this:

Platform Power → Input Protection → EMI Filter → DC-DC Converter → Load

And this is where the architectural question begins:

Should each function be implemented using a separate component or module, or can these functions be integrated into a single Power Conversion solution?

Four Different Requirements That Ultimately Meet at the Same Power Supply

One of the reasons Power Conversion design for military systems becomes complex is that the requirements do not come from a single standard.

Each standard addresses a different aspect of the system, but ultimately these requirements meet within the same power chain.

MIL-STD-1275 – Military Vehicle Power Environment

In military vehicle systems, MIL-STD-1275 defines the electrical power environment to which the equipment is connected.

A system defined as 28VDC does not necessarily provide a stable 28V at all times. Equipment connected to it must take into account the required operating range and the voltage events relevant to the application.

Therefore, selecting a DC-DC converter for a military vehicle is not simply a matter of checking whether its input voltage range includes 28V.

Input Protection circuitry may be required ahead of the converter to protect both the converter and the load from conditions outside the normal operating range.

MIL-STD-704 – Aircraft Power Environment

The situation is similar in airborne systems, although the electrical environment and requirements are different.

MIL-STD-704 addresses the characteristics of aircraft electrical power systems, including various DC and AC systems depending on the platform.

Here too, compatibility with the nominal voltage alone is not sufficient.

The operating ranges and relevant voltage events must be considered, and the entire power chain must be designed accordingly.

MIL-STD-461 – EMI and EMC

Even after the input voltage and converter protection requirements have been addressed, another challenge remains: electromagnetic interference.

DC-DC converters are high-frequency switching systems. Their switching operation can generate conducted and radiated interference, while the converter itself must also continue to operate correctly in the presence of external interference.

MIL-STD-461 defines EMI and EMC requirements and test methods for electrical and electronic equipment and subsystems.

From a power-chain perspective, this means that a substantial EMI Filter may sometimes be required between the power source and the DC-DC converter.

One of the important challenges in this area is CS101, a Conducted Susceptibility test in the lower-frequency range.

A conventional external filter solution may require substantial magnetic and capacitive components, consume significant space and volume, and affect both system weight and efficiency.

For this reason, EMI Filter design is not necessarily something that can simply be added at the end of a project. In space-constrained systems or higher-power applications, it can become a major part of the power supply architecture from the very beginning of the design process.

MIL-STD-810 – The Environment in Which the Entire System Must Operate

MIL-STD-810 adds another dimension.

Even an excellent electrical solution is not enough if the product is not suitable for the environmental conditions of the application.

Temperature, vibration, shock, and installation conditions can influence component selection, mechanical design, cooling method, and system reliability.

The final solution is therefore much more than an electrical schematic.

It is a combination of Power Conversion, Protection, EMI/EMC, Thermal Design, and Mechanical Design.

The Problem with the Traditional Approach: Every Requirement Adds Another Layer

When each requirement is addressed separately, it is easy to end up with a modular architecture consisting of several different units.

You start with a DC-DC converter.

Then you add protection circuitry to handle the input power environment.

Next comes an EMI Filter to address interference requirements.

If the filter is not sufficient, additional components are added.

Then everything must be interconnected, the generated heat must be dissipated, space must be found inside the enclosure, and the complete assembly must be tested to determine how all the individual elements behave when operating together.

Each additional component may be justified on its own, but at the system level, the costs begin to accumulate.

And not only the financial cost.

The impact may include:

  • Larger volume
  • Higher weight
  • More components
  • Additional wiring and connectors
  • A more complex BOM
  • Additional power losses
  • Greater thermal management requirements
  • More design and integration work
  • Additional potential points of failure
  • More engineering time required to bring the complete system to the required performance level

This leads to an important point:

The smallest unit on the lab bench is not necessarily the smallest solution in the final system.

A very compact DC-DC converter may look attractive on its own. But if using it requires a large external filter, protection circuitry, a PCB, and additional components, then the size, weight, and efficiency of the entire power chain must be evaluated, not just those of the converter.

Instead of a Collection of Components – An Integrated Military Power Solution

The integrated approach starts from a different point.

Instead of first selecting a DC-DC converter and then trying to protect and filter it, the complete operating environment of the system is defined from the beginning.

What is the power source?

What voltage events are expected?

What EMI/EMC requirements apply?

How much power is required?

What output voltages are needed?

How much space is available?

How will heat be dissipated?

Under what environmental conditions must the product operate?

Once these requirements are known, the Power Conversion, protection, and filtering functions can be designed as a single system.

In Gilgal Power solutions, functions such as:

Input Protection + EMI Filtering + DC-DC Conversion

can be integrated into a single compact Power solution according to the requirements of the application.

The objective is not simply to place several functions inside the same enclosure.

The objective is to design them together.

When the protection circuitry, filter, and converter are designed as one system, optimization can be performed at the system level rather than optimizing each individual block separately.

This can be particularly important in applications where every centimeter, every gram, and every watt of power loss matters.

The Advantage Is Not Just Size – It Is Integration

Reducing Size, Weight and Power, commonly referred to as SWaP, is a clear advantage of an integrated solution, but it is not the only one.

When Input Protection, EMI Filtering, and DC-DC Conversion are designed separately, each unit must operate correctly with the units before and after it.

The filter affects the converter.

The converter affects the filter.

Protection circuitry adds resistance, capacitance, and in some cases additional power losses.

Even the wiring and connectors between the units are not electrically transparent.

In some cases, combining components that each perform well individually does not guarantee that the complete system will operate optimally.

For example, an EMI Filter is not simply a component that “cleans up noise.” It creates an electrical network with its own dynamic characteristics, and the interaction between the filter and the input impedance of a switching converter must be considered during the design process.

When the filter and converter are designed together, the complete system can be optimized rather than optimizing each unit separately.

This is one of the reasons why an Integrated Power solution can provide benefits that go far beyond the physical space savings.

Built-In Input Protection – Designing for the Input Environment from the Start

In a military system, the power source is not an ideal laboratory power supply.

For this reason, Input Protection is one of the important stages at the system input.

Depending on the platform and application requirements, the protection circuitry may need to handle various voltage events and prevent them from reaching the DC-DC Converter and downstream load at potentially damaging levels.

In a traditional architecture, this protection may be implemented using a separate module or a collection of external components.

In an integrated solution, the protection stage can be designed as an integral part of the Power Conversion system.

The advantage is that the protection can be matched to the converter, the required power level, and the application’s input profile rather than adding a generic protection solution ahead of an existing converter.

This approach is particularly relevant for systems that must operate within the electrical environments defined by MIL-STD-1275 for military vehicles or MIL-STD-704 for aircraft systems.

It is important to emphasize that the presence of input protection does not automatically mean that the system meets every requirement of a particular standard.

The solution must be defined and tested according to the project requirements, platform, and applicable revision of the standard.

Built-In EMI Filtering – When the Filter Becomes Part of the Power Supply

EMI Filtering is one area where the advantages of integrated design can be particularly significant.

An external EMI solution can look simple on paper:

Add Inductors, Capacitors, and additional filtering components ahead of the converter.

But as EMI/EMC requirements become more demanding, the filter can quickly grow.

More inductance.

More capacitance.

More volume.

More weight.

More losses.

In a space-constrained system, the filter that was intended to “simply help the converter pass the test” can become one of the largest elements in the entire power chain.

CS101 – An Excellent Example of the Challenge

One of the challenging tests within MIL-STD-461 is CS101 – Conducted Susceptibility, Power Leads.

The test evaluates the ability of equipment to continue operating when a low-frequency disturbance is coupled onto the power leads.

From a Power Electronics perspective, this presents a different challenge from filtering high-frequency interference alone.

A conventional solution may require substantial passive components to achieve the required attenuation over the relevant frequency range.

The result can be a relatively large and heavy filter and, in some cases, reduced efficiency due to additional losses in the power chain.

Gilgal Power has particular expertise in addressing CS101 challenges using compact Power and Filtering solutions, with the goal of reducing the space and weight required compared with conventional filtering approaches.

Instead of treating CS101 as a problem discovered during EMC testing and then attempting to solve it by adding an external filter, the requirement can be incorporated into the power supply design from the earliest stages of the project.

It is a small change in the way the project is defined, but it can make a major difference in the final architecture.

When the Protection, Filter, and Converter Are Designed Together

This is where the entire concept comes together.

Instead of:

Protection Module + EMI Filter + DC-DC Converter

the system can be designed as:

Protection + Filtering + Conversion

within a single electrical architecture.

This does not mean that every application will necessarily use the same solution.

Quite the opposite.

The advantage is the ability to tailor the architecture to the actual requirements of the project:

  • Input voltage and platform
  • MIL-STD-1275 or MIL-STD-704, depending on the application
  • Applicable MIL-STD-461 requirements
  • CS101 requirements
  • Required output voltage or voltages
  • Power
  • Isolation, when required
  • Size and weight constraints
  • Cooling conditions
  • Operating temperature
  • Mechanical and environmental requirements

The customer therefore does not begin with the question:

“Which DC-DC Converter is right for my application?”

Instead, the better question is:

“What power chain do I need to operate my system under the required electrical, environmental, and compliance conditions?”

That is the difference between selecting a component and designing a Military Power Solution.

One Solution for Multiple System Requirements

One of the key advantages of an integrated approach is the ability to address multiple requirements from the earliest stages of power supply design.

In a military vehicle system, for example, the design can begin with the input power environment requirements of MIL-STD-1275F, incorporate the applicable EMI/EMC requirements of MIL-STD-461, and include the DC-DC Conversion as part of the same system.

The emphasis on MIL-STD-1275F is important. It is not enough to define the system simply as “28VDC” or even to refer generally to MIL-STD-1275. When a project requires Revision F, the input stage must be designed according to the applicable requirements of that revision.

Designing compact solutions for MIL-STD-1275F applications is a key area of expertise for Gilgal Power, particularly when EMI Filtering and DC-DC Conversion must also be integrated into the same unit.

In an airborne system, the same principle can be applied to the MIL-STD-704 power environment.

At the same time, the mechanical and thermal design of the product can be developed according to the environmental conditions of the application and the applicable MIL-STD-810 requirements.

The result is an architecture in which the standards are not treated as four separate “boxes,” but as different groups of requirements that influence the same Power solution.

It is also important to distinguish between these standards.

MIL-STD-1275F and MIL-STD-704 are not substitutes for MIL-STD-461, and MIL-STD-461 is not a substitute for MIL-STD-810.

Each addresses a different aspect of the system.

The advantage is that the applicable requirements from each standard can be incorporated into the design of the same Power unit.

MIL-STD-1275F + MIL-STD-461 Within the Same Architecture

Consider a system installed in a military vehicle.

On one hand, the input must be designed for the vehicle’s electrical power environment and the applicable requirements of MIL-STD-1275F.

On the other hand, the same unit may also be required to meet EMI/EMC requirements defined by MIL-STD-461.

The power chain is therefore not simply:

28VDC → DC-DC → Load

Instead, the system must address several challenges simultaneously:

  • MIL-STD-1275F input power environment
  • Voltage events and input protection
  • EMI Filtering
  • Applicable MIL-STD-461 requirements
  • DC-DC Conversion
  • Efficiency and thermal management

In a traditional approach, each requirement can be addressed using a separate stage.

However, when MIL-STD-1275F compliance is required together with demanding EMI/EMC requirements, the external protection and filtering solution can become significantly larger and more complex than the converter itself.

This is where one of the key advantages of Gilgal Power becomes particularly relevant.

Instead of starting with a standard DC-DC Converter and adding layers of protection and filtering around it, the design can begin with the MIL-STD-1275F + MIL-STD-461 requirements and integrate Input Protection, EMI Filtering, and DC-DC Conversion as a single system.

This approach enables optimization of size, weight, efficiency, and performance at the complete system level.

MIL-STD-704 + MIL-STD-461 in Airborne Systems

The same principle applies to airborne systems.

Here, the input power environment is determined by the aircraft electrical system and the applicable requirements of MIL-STD-704, while EMI/EMC requirements may come from MIL-STD-461.

Again, there is no engineering reason to necessarily treat these requirements as completely independent systems.

When the requirements are known in advance, the Input Stage, EMI Filtering, and Power Conversion can be designed as an integrated system.

For airborne applications, where weight and volume are often critical parameters, this level of integration can provide particularly significant benefits.

What Is the Role of MIL-STD-810?

MIL-STD-810 does not define input power quality and is not an EMI standard.

It adds a completely different layer: the physical operating environment.

For example:

  • High and low temperatures
  • Vibration
  • Shock
  • Additional environmental conditions according to the required profiles and test methods

When several separate modules are installed in a system, each has its own enclosure, connections, mounting points, and thermal behavior.

An integrated solution allows the mechanical and thermal considerations to become part of the overall power unit design.

For example, instead of distributing power losses across several interconnected units, the thermal path of the complete system can be designed from the start.

Similarly, component placement, mechanical interfaces, and enclosure design can be addressed as part of the product design rather than as constraints created after several separate units have been connected together.

Integrated vs. Discrete – A System-Level Comparison

When comparing the two approaches, it is important not to compare only the price or physical size of the DC-DC Converter.

The complete system should be compared.

Parameter Discrete Solution Integrated Solution
DC-DC Conversion Separate converter Integrated into the system
MIL-STD-1275F Input Protection Requires a suitable protection solution ahead of the converter Can be designed as part of the Power solution
EMI Filtering External filter Can be integrated into the solution
MIL-STD-461 / CS101 May require substantial external filtering and components Requirements can be incorporated into the system design
Component Count Typically higher Can be reduced
Wiring and Connections More interconnections between units Interconnections can be reduced
Volume Accumulates across multiple units Can be optimized at the system level
Weight Separate enclosures, connectors, and components Potential for weight reduction
Efficiency Affected by losses in each separate stage Can be optimized across the complete system
Thermal Design Multiple heat sources and units Thermal design of the system as a whole
EMI/EMC Filter-to-converter compatibility must be addressed during integration Filter and converter can be designed together
Integration Responsibility of the system designer A larger part of the integration can be handled at the power-supply level
Application-Specific Design Combination of existing products Can be designed around project requirements

The last point is particularly important.

An Integrated solution is not necessarily a single off-the-shelf product suitable for every military system.

The real value lies in the ability to start with the system requirements and build the Power solution around them.

For a military vehicle application, for example, the starting point may be:

MIL-STD-1275F + MIL-STD-461 / CS101 + Required DC Outputs

and from there, the complete power solution can be designed.

Fewer Components Can Also Mean Lower Integration Risk

A system built from multiple modules has more interfaces.

Every connector, cable, PCB, and electrical interface is another element that must be specified, purchased, assembled, and tested.

In addition, when a problem appears during system testing, its source must be identified.

Is the converter generating the interference?

Is the filter unsuitable?

Is the wiring affecting performance?

Is there an interaction between two modules?

Did a change intended to solve an EMI problem create a thermal issue or reduce efficiency?

Reducing the number of interfaces can reduce some of this integration complexity.

This is why the advantage of an Integrated Military Power Solution is not simply a “smaller box.”

The objective is a system that is easier to integrate, with fewer external components and fewer variables for the customer to resolve.

When Is an Integrated Military Power Solution Particularly Valuable?

Not every system requires an integrated solution.

If the input power environment is relatively simple, there are no special EMI/EMC requirements, and sufficient space is available, a standard DC-DC converter with a few external components may be an excellent solution.

The advantages of an Integrated Military Power Solution become more significant when several constraints exist simultaneously.

For example:

  • MIL-STD-1275F requirements apply
  • Stringent MIL-STD-461 requirements must be addressed
  • CS101 presents a significant challenge
  • Space is limited
  • Weight is a critical parameter
  • High efficiency is required
  • Heat dissipation is limited
  • Significant power is required within a small volume
  • Environmental and mechanical requirements apply
  • The customer wants to reduce external components and integration effort

The more of these requirements that exist within the same project, the greater the potential benefit of designing the power system as a whole.

Do Not Select a DC-DC Converter Based on the Datasheet Alone

One common mistake in system design is to start with a product that appears suitable based on its basic specifications.

For example:

Input: 18-36VDC
Output: 12VDC
Power: 300W

On paper, such a converter may appear suitable for a 28VDC system.

But these are only three parameters within a much larger set of system requirements.

Before selecting the converter, several additional questions should be considered:

Is the input voltage range suitable for the actual electrical environment?

What happens during a Transient or Surge?

What Input Protection is required?

What are the EMI/EMC requirements?

Is MIL-STD-461 required?

Is CS101 applicable?

How large will the required filter be?

What will the overall efficiency be after adding the protection and filtering stages?

How much heat will the complete system generate?

And how much space will all the components occupy after integration?

A proper comparison between solutions should therefore not be:

DC-DC vs. DC-DC

but rather:

Complete Power Chain vs. Complete Power Chain

Size, Weight and Power – Looking at the Real SWaP

SWaP – Size, Weight and Power – is a key consideration in many military and aerospace systems.

But here too, it is important to measure the right thing.

If one converter is 20% smaller but requires a large external filter, an additional protection module, a PCB, and connectors, the final system may actually be larger and heavier.

The same principle applies to efficiency.

Comparing only the efficiency of the DC-DC converter does not provide the complete picture if several additional stages ahead of it introduce power losses.

At the platform level, what matters is the performance of the entire power chain.

For this reason, when designing a compact military power system, it is important to evaluate:

Total Size + Total Weight + Total Losses + Total Thermal Load

rather than considering only the specifications of an individual component.

Gilgal Power Military Power Solutions

Gilgal Power develops Power Conversion solutions for military and aerospace applications where electrical requirements, EMI/EMC, SWaP constraints, and environmental conditions must all be addressed.

Instead of treating the DC-DC Converter, Input Protection, and EMI Filter as unrelated products, they can be designed as parts of a single solution tailored to the system requirements.

Key areas of focus include:

  • Military DC-DC solutions
  • Input Protection
  • EMI Filtering
  • Solutions for MIL-STD-1275F
  • Solutions for MIL-STD-704
  • Design according to MIL-STD-461 requirements
  • Specialized solutions for CS101 challenges
  • Mechanical and thermal design for military applications
  • Custom solutions according to project requirements

The objective is not to add as many functions as possible to the product.

The objective is exactly the opposite:

To meet the system requirements with a smaller, more efficient solution that is easier to integrate.

Start with the Requirements – Not the Catalog

For projects of this type, the right starting point is not necessarily selecting a Part Number.

The first step is to understand the operating environment.

The better the engineering requirements are defined at the beginning of the project, the easier it becomes to determine whether a standard solution is suitable or whether a customized solution is required.

Checklist for Defining a Military DC-DC Solution

Before selecting a solution, it is recommended to define as many of the following parameters as possible:

Platform

  • Military vehicle
  • Aircraft
  • Ground system
  • Other platform

Input Voltage

  • Nominal voltage
  • Continuous input voltage range
  • Type of power system

Output Voltage

  • Required output voltage
  • Number of outputs
  • Accuracy and Regulation, when applicable

Power

  • Continuous power
  • Peak Power, if applicable
  • Load characteristics

Standards and Requirements

  • MIL-STD-1275F
  • MIL-STD-704
  • MIL-STD-461
  • CS101 and other EMI/EMC requirements
  • MIL-STD-810
  • Additional project or platform-specific requirements

Mechanical Constraints

  • Maximum dimensions
  • Maximum weight
  • Mounting method
  • Required connectors

Thermal Requirements

  • Operating temperature
  • Baseplate / Conduction Cooling
  • Air Cooling, if available
  • Heat dissipation limitations

Additional Requirements

  • Isolation
  • Hold-up
  • Inrush Current
  • Remote On/Off
  • Monitoring
  • Protections
  • Other system-specific requirements

Not all of these parameters must necessarily be known at the initial stage.

However, the earlier the input environment, EMI requirements, power level, and SWaP constraints are defined, the easier it is to avoid a situation in which a converter selected early in the project later requires a large collection of external solutions.

The Bottom Line

In a military system, the power supply is much more than a voltage converter.

It sits at the intersection of the platform power system, the electronic load, EMI/EMC requirements, environmental conditions, and the mechanical constraints of the system.

MIL-STD-1275F introduces significant input power challenges for equipment connected to military vehicle electrical systems.

MIL-STD-704 addresses the aircraft electrical power environment.

MIL-STD-461 adds the EMI and EMC requirements, including significant challenges such as CS101.

MIL-STD-810 brings mechanical and thermal environmental conditions into the picture.

Each of these requirements can be addressed by adding another layer to the power chain.

Or the design can start with the complete system.

Input Protection + EMI Filtering + DC-DC Conversion

When these functions are designed together, external components can be reduced, SWaP can be optimized, and integration complexity can be minimized.

This is the approach behind Gilgal Power’s Military Power solutions.

At Amironic, we work together with Gilgal Power to tailor Power Conversion solutions to the application requirements, from defining the input power environment and applicable standards through to integrating the power solution into the system.

Designing a system with MIL-STD-1275F, MIL-STD-704, MIL-STD-461, or CS101 requirements?

Send us your input voltage, output voltage, power requirements, applicable standards, and size and weight constraints, and we will evaluate how Input Protection, EMI Filtering, and DC-DC Conversion can be integrated into a single compact solution.

Key Terms

Military DC-DC Converter
A voltage converter intended for use in military systems and designed according to the electrical, environmental, and system-level requirements of the application. Compatibility with the required input and output voltages alone does not indicate compliance with any specific military standard.

Integrated Military Power Solution
An architecture in which several power-chain functions, such as Input Protection, EMI Filtering, and DC-DC Conversion, are designed as a single system rather than implemented using multiple separate modules.

Input Protection
Circuits and components designed to protect the power supply and the system from abnormal voltage and current conditions originating from the power source. The required type of protection depends on the platform and project requirements.

EMI Filter
A filtering network designed to reduce the propagation of electromagnetic interference through the power lines. In military systems, filter design can have a significant impact on the size, weight, and efficiency of the complete power chain.

MIL-STD-1275F
A revision of the U.S. military standard addressing the characteristics of DC electrical power systems in military vehicles and the electrical environment to which connected equipment is exposed. When a project requires MIL-STD-1275F, the solution should be designed for the applicable requirements of Revision F rather than relying on a general reference to MIL-STD-1275.

MIL-STD-704
A U.S. military standard defining the characteristics of aircraft electrical power systems. It applies to various DC and AC power systems depending on the platform and application.

MIL-STD-461
A U.S. military standard defining EMI and EMC requirements and test methods for electrical and electronic equipment and subsystems.

CS101 – Conducted Susceptibility, Power Leads
A test within MIL-STD-461 that addresses equipment susceptibility to conducted disturbances coupled onto the power leads over the frequency range defined by the test. For power supplies, meeting this requirement can present a significant filter design challenge.

MIL-STD-810
A U.S. military standard containing environmental test methods for conditions such as temperature, vibration, and shock. The applicable methods and test profiles depend on the platform and application.

SWaP – Size, Weight and Power
A term describing the combined impact of system size, weight, and power consumption or energy efficiency. In military and aerospace systems, SWaP optimization can be a key design requirement.

Power Front End
The section of the power system located between the power source and the load or subsequent conversion stages. Depending on the architecture, it may include Input Protection, EMI Filtering, regulation, and power conversion.

Discrete Power Architecture
An approach in which functions such as Input Protection, EMI Filtering, and DC-DC Conversion are implemented using separate components or modules.

Integrated Power Architecture
An approach in which multiple functions within the power chain are designed together to optimize the complete system.

Frequently Asked Questions – FAQ

Is an 18-36VDC Converter Automatically Suitable for a 28VDC Military System?

No.

28VDC is a nominal voltage. Having a continuous input range that includes 28V does not guarantee that the converter can withstand all voltage events and requirements associated with a military electrical power environment.

If the system requires MIL-STD-1275F, the complete input power chain should be evaluated against the applicable requirements of the standard.

What Is the Difference Between a Standard DC-DC Converter and a Military DC-DC Converter?

A DC-DC converter primarily performs voltage conversion.

In a military application, additional requirements may apply to the input power environment, transients, EMI/EMC, temperature, vibration, shock, cooling, and mechanical constraints.

The product should therefore be evaluated as part of the complete system rather than solely according to its Input, Output, and Power specifications.

What Is the Advantage of a Built-In EMI Filter?

Integrating the EMI Filter with the DC-DC Converter allows both stages to be designed as a single system.

This approach can reduce external components, volume, weight, and interconnections while allowing the interaction between the filter and converter to be optimized.

The advantage can be particularly significant when stringent MIL-STD-461 requirements apply.

Why Can CS101 Be Particularly Challenging for Power Supplies?

CS101 addresses disturbances coupled onto the power leads over a relatively low-frequency range.

Conventional passive solutions designed to achieve significant attenuation in this range may require relatively large magnetic and capacitive components.

As a result, CS101 can have a significant impact on filter size, weight, efficiency, and the overall power supply architecture.

Does Compliance with MIL-STD-1275 Automatically Mean Compliance with MIL-STD-1275F?

Not necessarily.

When a project specifically requires MIL-STD-1275F, it is important to verify compliance with the required revision and the specific requirements applicable to the system.

A general MIL-STD-1275 statement, or compliance with an earlier revision, should not be assumed to mean automatic compliance with MIL-STD-1275F.

Does MIL-STD-1275F Include MIL-STD-461 Requirements?

No.

These are separate standards addressing different aspects of the system.

MIL-STD-1275F addresses the electrical power environment of military vehicles, while MIL-STD-461 addresses EMI and EMC.

Requirements from both standards may apply to the same system, so the power solution may need to be designed accordingly.

Does MIL-STD-704 Include EMI/EMC Requirements?

No.

MIL-STD-704 addresses the characteristics of aircraft electrical power systems. EMI/EMC requirements may come from other standards, including MIL-STD-461.

An airborne system may therefore need to address MIL-STD-704 and MIL-STD-461 simultaneously.

Is an Integrated Solution Always Better Than Several Separate Modules?

No.

In a relatively simple system, a Discrete solution may be more suitable, readily available, and cost-effective.

The advantages of an Integrated solution become more significant when stringent requirements for Input Protection, EMI/EMC, SWaP, efficiency, Thermal Management, and environmental performance must be addressed simultaneously.

Can an Integrated Solution Improve Efficiency?

It can enable better optimization of efficiency at the system level.

In a Discrete solution, losses occur in each stage, including protection circuitry, filters, wiring, and power conversion.

When these stages are designed together, Total System Efficiency can be evaluated and optimized rather than focusing only on the efficiency of the DC-DC Converter itself.

Can MIL-STD-1275F, MIL-STD-461, and DC-DC Conversion Be Integrated into a Single Unit?

A Power solution can be designed in which Input Protection, EMI Filtering, and DC-DC Conversion are integrated within the same architecture according to the project requirements.

This is one of Gilgal Power’s areas of expertise, particularly in applications where MIL-STD-1275F, MIL-STD-461 requirements, and CS101 challenges must be addressed together with size, weight, and efficiency constraints.

What Information Is Needed to Select the Right Solution?

A good starting point is the input voltage, output voltage, required power, platform, and applicable standards.

Information about size and weight constraints, operating temperature, cooling, isolation, connectors, and EMI/EMC requirements allows the Power solution to be matched more accurately to the application.

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