MCF > Detailed Design and Analysis > Electrical >

Circuit Analysis

Scope and Description

This topic covers the analysis of the electrical circuits implemented in space electronics. These analysis are used to verify that circuit designs can satisfy mission requirements even as EEE part parameters deviate from their nominal values due to tolerances, degradation, temperature, and radiation effects. The analyses typically employed by space hardware developers include Failure Mode and Effects Analysis (FMEA), Failure Mode, Effects, and Criticality Analysis (FMECA), Part Stress Analysis, and Worst Case Circuit Analysis (WCCA).

Resources under this topic include standards and methods for performing these analyses, software tools for computing complex inputs to these studies, and NASA lessons which promote the application of these analyses.

Best Practices and Lessons Learned

  • Without a formal process such as FMECA for assessing the effects of failure modes, there is no consistent and straightforward way to verify design integrity. Always use a systematic approach that starts at either a piece part or circuit functional block level and work up through all subsystems.
  • The absence of a structured worst case circuit analysis (WCCA) approach jeopardizes design integrity. This greatly increases the likelihood of qualification test failures and/or late-stage design modifications.
  • Always seek independent review of circuit analyses to ensure that no design defects go undetected.

Resources

White Paper
Reliability Analysis Center

This document is an in-depth guide for FMECA. It includes background with references to other relevant ... documents, processes and methods, examples, and references to software tools for FMECA.

This page in the NASA Public Lessons Learned System recommends that a formal WCA process is established ... for all design efforts. While following this guidance is not practical for all smallsat teams, this page provides motivation to consider integrating WCAs into your design process.

This page in the NASA Public Lessons Learned System recommends that a formal FMECA process is established ... for all design efforts. While following this guidance is not practical for all smallsat teams, this page provides motivation to consider integrating FMECAs into your design process.

White Paper
NASA

This page in the NASA Public Lessons Learned System emphasizes that failure to perform stress analysis ... for space hardware can severely limit part reliability. It provides specific details and motivation for this guidance.

This book provides detailed information on Failure Mode and Effects Analysis (FMEA) from an applications ... standpoint. It includes detailed case studies, study problems, and tips. It covers System FMEAs, Design FMEAs, Process FMEAs, Maintenance FMEAs, Software FMEAs, and more. Fault Tree Analysis, Design Review Based on Failure Mode, Reliability-Centered Maintenance, Hazard Analysis, and FMECA (which includes criticality analysis) are also covered.

Software Tool
Cadence Design Systems

The OrCAD PSpice Designer is a powerful software tool for building, analyzing, and simulating analog ... and mixed-signal design. It can be used for a wide variety of purposes: prototyping small circuits, complex system design, or validating reliability. It allows for easy iteration before proceeding to layout and fabrication.

This guide describes procedures for conducting FMEA analysis. Functional, interface, and detailed FMEA ... are covered. It also includes pre-analysis items like FMEA planning and functional requirements analysis and post-analysis items like failure latency analysis, FMEA verification, and documentation. These procedures are provided with consideration for reliability, cost, and speed.

White Paper
Aerospace Corporation

This guide was produced because failure modes, effects, and criticality analysis (FMECA) was not being ... used effectively to help manage risk. It provides detailed guidance for the unmanned space vehicle and launch vehicle industries on how to best leverage FMECA for space mission assurance.

This is a guidebook of best practices for evaluating Worst Case Circuit Analysis (WCCA). Guidance given ... ranges from general principles to circuit-level detailed guidance. It thoroughly discusses a wide variety of WCCA topics, including programmatics and process planning.

White Paper
AEi Systems

As its title states, this resource details exactly what WCCA is, when it should be applied, and why. ... It is a great introduction to WCCA.

White Paper
System Reliability Center

This resource outlines methods for performing worst case circuit analysis (WCCA) correctly. It also contrasts ... various WCCA analysis methods and compares their advantages and disadvantages.

White Paper
NASA

This page in the NASA Public Lessons Learned System describes the importance of establishing a "mandatory ... closed-loop system for detailed, independent, and timely technical reviews of all analyses performed in support of the reliability/design process." These reviews are important for detecting design defects.

Software Tool
Vanderbilt University

SEAM is a web application for modeling assurance cases integrated with system models. SEAM supports the ... Goal Structuring Notation (GSN) standard and a subset of the SysML system modeling standard. Documentation and video tutorials are provided.

Standard
US Department of Defense

This Military Standard provides requirements and procedures for performing Failure Mode, Effects ...
and Criticality Analysis (FMECA).

Get Involved