White Papers


A Practical Approach to Commercial Aircraft Data Buses
MIL-STD-1553 is a mature field proven technology that provides an ideal solution for emerging commercial aerospace applications. DDC is offering a wide variety of solutions based on this mature technology.
89 Pages, 6 MB
Rev: March 2011

Avionics Networking Technology
Avionics system architects have a wide variety of commercial off the shelf (COTS) choices for networking technologies. The challenge facing many system architects is choosing a cost effective technology that satisfies the functional requirements of the system. This paper provides insight into some of the key architectural features of two of the most popular emerging networking technologies used in avionics today, namely, Fibre Channel and Ethernet. An overview of each architectural feature is provided along with a discussion of the system-level benefits associated with the feature. A new approach called high speed 1553 is also explored. The goal of this paper is not to evaluate these technologies against an arbitrary set of criteria to determine which is better for avionics systems, but rather to provide insight into the benefits of each technology. In reality, no one networking architecture will be “best” for all applications. Each application will contain its own unique requirements that will shape the selection decision. In many cases, the optimal solution may be a combination of several different networking technologies.
28 Pages, 284 KB

Buses and Networks for Contemporary Avionics
MIL-STD-1553 has served the needs of military system integrators for over 30 years, particularly in the area of command and control applications. Nevertheless, contemporary applications such as high-speed digitized sensors, file transfers, processor clusters, and displays require much higher data rates than 1553’s 1Mb/s. For some environments, particularly for legacy aircraft, the optional solution is to transmit faster data rates over existing 1553 buses. However, there are other applications that can accommodate and benefit by the deployment of gigabit or multi-gigabit copper or optical switched fabric networks. In addition to MIL-STD-1553, this paper presents and comments about several avionics networking technologies including High-Speed 1553, Fibre Channel, Gigabit Ethernet, and ARINC 664, a form of profiled Ethernet.
31 Pages, 658 KB
Rev: Nov 2007

DDC Replacements for Obsolete Aeroflex Transceivers
Aeroflex Colorado Springs (Aeroflex) announced on April 17th, 2009 that both UT63M105 & UT63M125 (Standard Microcircuit Drawing 5962-88644), 15-Volt, MIL-STD-1553 Bus Transceivers have reached End-of-Life (EOL) status and are out of production. DDC is pleased to offer the following MIL-STD-1553 Bus Transceivers as suggested replacements for the above referenced Aeroflex EOL components. DDC replacements are lower-power and are electrically / mechanically compatible to the discontinued items which should preclude the need for a board re-design due to the transceiver obsolescence issue. There are manageable differences in both the pinout (not all pins utilized) and mechanical characteristics (through the use of standoffs, spacers, and lead forming variations) as well as minor variations in AC and DC electrical parameters due to wafer foundry and DDC’s unique design. The end user needs to compare the differences between the components and determine if they are acceptable in the customer’s specific application.
12 Pages, 917 KB
Rev: July 13 2011

Distributed and Reconfigurable Architecture for Flight Control Systems
This white paper discusses some evolutions for Flight Control System (FCS) and how to build alternative FCS using low-cost and safe architectures with less hardware and software resources. The paper presents a full distributed reconfigurable architecture for FCS based on smart actuators and digital communication network where all system functions are distributed to simplex Flight Control Computer (FCC) nodes and remote actuator electronics nodes (FCRM) with communication between FCC and FCRM based on a MIL-STD-1553 bus.
13 Pages, 1 MB
Rev: March 2011

High Performance 1553
This white paper provides a summary of DDC’s initial study into the feasibility of running higher speed over legacy MIL-STD-1553 data buses. The results of DDC’s analysis is that for some MIL-STD-1553 buses there is sufficient bandwidth to implement a broadband system in which legacy 1 Mbps 1553B waveforms could coexist with new 200 Mbps waveforms, thus providing for an increment high speed communication channel to existing MIL-STD-1553 buses.
16 Pages, 2 MB
Rev: March 2011

IRIG 106 Chapter 10 Standardizes MIL-STD-1553 Data Recording
In an effort to reap the benefits of standardization for data recorder file formats, the Range Commanders Council (RCC) and others in the US Air Force instrumentation community developed the IRIG 106 Chapter 10 standard. IRIG 106 Chapter 10 provides interoperability for such applications as test range telemetry, flight test instrumentation, mission recorders, video/data servers; surveillance and reconnaissance; health and usage monitoring; mission planning, debriefing, and training; and flight operations. In addition to file formats, Chapter 10 defines the operation of various recorder and removable media (data cartridge) interfaces. IRIG 106 Chapter 10 includes specific formats for several types of flight data, including MIL-STD-1553 buses, PCM, analog, computer-generated data, images, discretes, UARTs, IEEE 1394, parallel, IRIG time, video, and voice. In addition, Chapter 106 provides standardization of time bases.
16 Pages, 303 KB
Rev: 11/2007

MIL-STD-1553 Evolves with the Times
MIL-STD-1553 combines a robust physical layer with a deterministic protocol making it ideally suited for use in commercial aerospace systems. While MIL-STD-1553’s 1 megabit-per-second data rate is still adequate for a large number of applications, there are systems that require higher rates. This white paper discusses two approaches for increasing the bandwidth of MIL-STD-1553 that are gaining momentum. The use of MIL-STD-1553 is not limited to military aircraft. MIL-STD-1553’s use is pervasive in military ground vehicles, military ships, and satellite systems. All of these applications share common requirements for a deterministic, fault tolerant data bus that will operate in relatively harsh environments.
15 Pages, 1 MB
Rev: March 2011

MIL-STD-1553 Goes Commercial
This paper explores some of the major attributes of MIL-STD-1553 and discusses why MIL-STD-1553 is an ideal choice for use in commercial aircraft systems.This paper explores some of the major attributes of MIL-STD-1553 and discusses why MIL-STD-1553 is an ideal choice for use in commercial aircraft systems.
10 Pages, 1 MB
Rev: March 2011

MIL-STD-1553 Physical Layer for Time-Triggered Networks
Time Triggered networking technologies such as TTP (Time Triggered Protocol) are beginning to be used in critical aerospace applications such as flight controls. While TTP provides stringent specifications for determinism and fault tolerance, it does not define a physical layer. TTP’s “de facto” physical layer, RS-485, includes shortcomings in a number of areas. The first white paper in this section presents the benefits of Mil-STD- 1553 over RS-485 as a physical layer for TTP. A second white paper presents the test results of a technology demonstration of 1553 as a physical layer for TTP.
35 Pages, 2 MB
Rev: March 2011

Total COTS Solutions for Embedded 1553
For contemporary avionics design, there’s a need to strategically allocate engineering resources without increasing time to market. This environment has engendered an increasing reliance on Commercial-off-the-Shelf (COTS) hardware and software, with a demand for total solutions that may be leveraged over a range of applications. This entails the needs for ruggedized hardware, along with re-usable high-level software tools. The COTS paradigm includes a focus on cost effectiveness and high reliability, along with obsolescence and end-of-life issues for both cards and components.
12 Pages, 199 KB
Rev: -

Synchro and Resolver

High-Reliabiltiy Position Control for Rugged Applications
Resolvers have a transformer type makeup of wire, core, and package material, thus allowing the resolver to handle much more stringent environmental conditions by locating only the resolver at the operational end keeping the more sensitive digital converter located on the processing circuit board. High temperature, humidity, dirt, oil, grease and vibration present no issues for resolvers. Resolvers are absolute; they retain position data when power is cycled off / on. Unlike incremental encoders, there is no need to pass a zero point to gain position.
19 Pages, 2 MB
Rev: 12/11

Motor Drives & Controllers

BLDC Motor Control in Demanding Environments
Motor drives and controllers are used in a variety of applications spanning a number of different environments. Military applications include antennas and sensor positioning, stabilized platforms, guns and cannons and turret control, ship steering/rotor control, bomb and missile fins, pumps, and simulation systems. Military and commercial aviation applications include actuators, landing gear, and emergency power units. For civil aircraft, the ongoing transition away from mechanical and hydraulic and towards “more electric” systems has increased the demand for high reliability electronic motor controllers.
12 Pages, 1 MB
Rev: January 2014

BLDC Motor Controllers...for Maximum Performance & Efficiency
Selecting the appropriate motor controller for your application does not have to be an impossible challenge, and this paper will help you focus in on the motor controller and drive solution best suited to meet your needs. Factors to consider vary by application across a variety of industries, including: military, space, commercial avionics, and industrial. Motor controller and drive applications can have varying functional and performance requirements, such as: environment, temperature, radiation tolerance, high accuracy speed and position control, constant and variable speed, rapid reversal, fixed position, and variable loads. While some motor controllers and drives are sufficient for simple, low stress conditions, demanding applications often require custom motor controllers and drives that are engineered for higher performance and efficiency, rugged conditions, and designed utilizing DSP-based, modular architectures that enable faster time-to-market, high TRL custom solutions, programming flexibility and scalable solutions.
12 Pages, 3 MB
Rev: October 2015

Fibre Channel

High Speed 1760 and FC-AE-1553
Network interfaces for future “smart” weapons will need to support applications such as transfers of terrain maps, target templates, program files, and digitized images and video. These applications will require the use of a high-speed data interface. For over 20 years, MIL-STD-1760, Aircraft/Store Electrical Interconnection System, has defined the interface between aircraft stores management computers, carriage stores (racks and launchers) and mission stores (bombs and missiles). This standard defines the connector, signal set definitions, topologies, types of interfaces, signal path requirements, and power; along with special requirements for MIL-STD-1553 bus interfaces. This includes a command set with detailed message formats, along with a defined protocol for mass data transfer. In 2008, the SAE AS-1A2 task group released AS5653, the High Speed Network for MIL-STD-1760, aka High-Speed 1760. This standard defines a gigabit-speed communication option for MIL-STD-1760. AS5653 specifies a network based on Fibre Channel, operating at 1.0625 Gb/s over a pair of 75 ohm coaxial cables, while other versions of the technology specify the same protocol over 150 ohm differential cable.
10 Pages, 641 KB
Rev: April, 2011

Test, Simulation, and Integration of Fibre Channel Networked Systems
Fibre Channel is a high-speed networking technology deployed on a number of military/aerospace platforms and programs. These include F-18E/F, F-16, F-35, B1-B, B-2, E-2D, the Apache Longbow and MMH helicopters, and AESA Radar. Applications for Fibre Channel include mission computers, processor and DSP clusters; data storage; video processing, distribution, and displays; sensors such as radar, FLIR, and video; serial backplanes and IFF.
17 Pages, 431 KB
Rev: 9/2006

Solid State Power Controllers

Performance Comparison: Solid State Power Controllers vs. Electromechanical Switching
The design of power distribution systems for modern ground and air platforms entails a number of challenges, including the needs for increased amounts of electrical power for C4I and other equipment; improved reliability; reduced weight, volume and power losses; along with capabilities to shed loads, and for enabling system prognostics and diagnostics. Solid State Power Controllers provide a number of advantages over electromechanical breakers and relays. SSPCs provide low loss switching with reducing EMI emissions, rapid short circuit protection, and I2t overload detection. I2t detection protects wiring, loads and SSPCs against overheating, while avoiding “nuisance trips” during periods of inrush currents. Relative to breakers and relays, SSPCs provide lower power dissipation, along with higher power weight and volume densities. By providing connectivity, SSPCs provide real time feedback to vehicle diagnostic computers. Data reported from SSPCs can be used for system-level diagnostics and prognostics, enabling predictive, condition-based maintenance, thereby providing increased availability and readiness. Reported data allows power management computers to make advance determinations of pending failures of generators, batteries, wiring, connectors, and loads.
18 Pages, 1 MB
Rev: July 2010

Japanese Translation:

Radiation Tolerant Microelectronics

Architectual Consequences of Radiation Performance in a Flash NAND Device
Single-event effects and total ionizing-dose testing was performed on a flash NAND device. The results are presented here and the consequences for error correction architectures are analyzed taking into account the fact that beginning-of-life flash devices are susceptible to data corruption with no external stress applied. The analysis indicates that many typical error correction architectures may be ineffectual because of the variety of radiation effects.
6 Pages, 502 KB
Rev: March 2017

Proton Cross-Sections from Heavy-Ion Data in Deep-Submicron Technologies
This paper reports on the calculation of proton SEU cross section from heavy-ion data using a number of different models. Model accuracy is checked using data on proton and heavy-ion cross sections from the published literature. The closed-form models developed with earlier semiconductor devices typically overestimated the proton cross section, and the difference increased with smaller feature sizes. The results emphasize that low LET heavy-ion data is crucial in determining the proton upset cross section.
7 Pages, 1 MB
Rev: December 2015

Proton Cross-Sections from Heavy-Ion Data in GaAs Devices
This paper reports on the calculation of proton SEU cross section from heavy-ion data in GaAs devices. A number of different models are used, however in each, accommodations must be made to account for the fact that the density and ionization energy of GaAs differs from that of Si. Model accuracy is checked using data on proton and heavy-ion cross sections from the published literature.
7 Pages, 1 MB
Rev: October 2001

SEE Testing of the 4 Gb Samsung and Spansion Flash NAND
Single event effect (SEE) testing was performed on the Samsung and Spansion 4 Gb NAND flash devices. Testing was performed up to LET = 41 MeV cm2/mg. The parts were characterized for a variety of SEE. Testing and analysis showed that MBU became more prevalent at higher LET values.
4 Pages, 207 KB
Rev: July 2016