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Analog Specs Just Test Them!

Analog Specs Just Test Them!

In the beginning– just test the specs.

Analog circuits have been around a long time. Consider a simple LRC circuit– the inputs and outputs are continuous wave forms.

This remains a key differentiator from digital circuits which operate on 1’s and 0’s.

Continuous waveforms require different test equipment and test techniques. Analog circuits have properties of impedance, 3Db points in the frequency domain, transform functions. They can be treated like a lumped circuit or a distributed circuit in which signal integrity and transmission line theory apply.

So testing is easy- you just test the specs. [Read more…]

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What Makes Memory Test Hard

What Makes Memory Test Hard

Just One More Thing

Memory circuits store 1’s and 0’s for you so that you can retrieve them later. The 1/0’s can represent data or instructions.

Today, no computing device operates without some memory. Memory devices store pictures, music, documents. How many USB (Unified Serial Bus) memory sticks do you have scattered on your desk?

Semiconductor memory comes in many flavors: Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), Read Only Memory (ROM), Erasable Programmable Memory (EPROM), NAND/NOR Memory (a.k.a. Flash), Solid State Drive (SSD). Without power volatile memories like SRAM and DRAM lose their stored values. Non-Volatile memories retain their stored value when power is absence. [Read more…]

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Digital Circuits and the Stuck at Fault Model

Digital Circuits and the Stuck at Fault Model

Fault_equivalence_example

Semiconductor Integrated Circuits (ICs) can have millions of digital circuits which can translate to billions of transistors.

I know these numbers can be intimidating, but I assure you the challenges of testing ICs started in the mid-late 1970’s.  Lots of effort has been put into Electronic Design Automation (EDA) systems and Design for Test (DFT) techniques to manage the development and application of digital circuit testing.

In the beginning these software programs and DFT techniques used the Stuck at Fault Model. [Read more…]

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Switch Verification

Switch Verification

Customer Usage Switch Verification

Here is an example of a common engineering development task. A design engineer needed a life test plan for a switch verification in a safety system. We jointly developed a plan by taking a system view of the component function, considered corporate and regulatory requirements, customized it to the supplier’s test capabilities, executed the plan, and made design changes to remove product defects. [Read more…]

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Manufacturing Test Approaches and Product Expectations

Manufacturing Test Approaches and Product Expectations

Depending upon the type of engineer you ask the word test evokes a different notion of goals and expectations.

Engineers who work on the design of semiconductors test that their designs meet the specifications.

This can be done pre-silicon and naturally verified in-depth on silicon.

Engineers concerned with manufacturing of a product test to find defects and to verify performance.

Similar approaches can be taken by both engineers though there exist differences in the amount of time. To be cost effective, a manufacturing test must be completed in as short a time as possible. Let’s continue to compare and contrast design validation with manufacturing test. [Read more…]

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Introduction to Testing 1 2 3

Introduction to Testing 1 2 3

Let’s Start At The Very Beginning

Before embarking on a complicated task one needs to have the basics understood.

In the musical “The Sound of Music,” Maria teaches the Von Trapp children to sing by first teaching them the musical scale.

She quickly discovers that the basics really do need to be learned one note at a time.

By the end of the “Do Re Mi” song she has them singing harmony while she sings a new melody with the words “When you know the notes to sing, you can sing most anything.” [Read more…]

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Characteristic 2 of an RCA Program

Characteristic 2 of an RCA Program

A Plan to Provide Program Resources

Who

Sometimes we get so used to managing without things that it becomes the way things are done. An astronaut giving a presentation at a conference I attended referred to this as “normalization of deviance.” In other words, we get so used to the way things are, that either right or wrong, they become the norm! Unfortunately, the obvious is many times ignored – because it is obvious. If you intend to have a sustainable Root Cause Analysis program, then there are things that must be done. People must be trained, reports must be written, analyses must be performed, and progress must be tracked and reported. Until a program becomes self-sustainable, it must continue to be driven. [Read more…]

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Analysis of Continuous Variables

Analysis of Continuous Variables

Telematics data analysis can be used to improve our understanding of how people use their vehicles. It is an objective source to validate product requirements. In cars and trucks, sensor signals are read by electronic modules share the data on a CAN bus. Some signals contain data for continuous variables. Some examples of continuous variables are vehicle speed, engine speed, engine torque, ambient temperatures, in-vehicle temperatures, pressures, voltages, and the battery state of charge. Another name for the continuous variables is parametric data. This CAN data is a rich source of information

[Read more…]

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Telematics Counting Data Analysis

Telematics Counting Data Analysis

In my prior article, an overview of vehicle telematics was provided. Telematics data includes time stamped records and fields containing count or parametric data recorded from the vehicle CAN bus. The count data is always a non-negative integer and the parametric data is stored as real numbers, generally in scientific format. This article focuses on the analysis of counting data.

Count data is used to monitor events, i.e., the number of trips, the days of operation, the calendar date, door open/close cycles, the number of engine starts/stops, or other variables. So, if a variable is selected for analysis, how can it be analyzed and a vehicle be characterized? How can fleets be analyzed? Can vehicle usage percentiles be determined?
[Read more…]

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The Bridge to Self Improvement

The Bridge to Self Improvement

Have you ever felt overwhelmed with too much to do? I imagine most of us have struggled with time management at one time or another. There are just too many things on our plate, and they never go away.

Some may attribute this burden to their life, or perhaps they are inefficient time managers, or something else. Regardless, I doubt many enjoy the feeling or the situation.

If only we could walk across the bridge to self improvement and be enlightened.

[Read more…]

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Telematics Data Analytics Overview

Telematics Data Analytics Overview

Product design, development, and reliability engineers need to verify that their product meets specifications, which include dimensional requirements, functional definitions, and life testing. How are the requirements validated?

Telematics data is collected to show how a vehicle has been operated. Fleets and retail data are stored on servers for engineering analysis. This data can be used to set new requirements or validate older requirements.

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