The methods included in this document are:

a. Voltage-Temperature Design Margins.

b. Voltage Interruptions and Transients.

c. Voltage Dropouts and Dips.

d. Current Draw Under a Number of Conditions.

e. Switch Input Noise

These methods are best applied during the Development stage but can be used at all stages (e.g. Pre-Qualification, Qualification or Conformity).

Measurement Philosophy

The main issues associated with contemporary mature electronic systems (non mechanical) are:

a. Requirements not properly defined (e.g. functionality, environment).

b. System interfaces.

c. Trouble Not Indicated (TNI).

A typical validation test program may not sufficiently address these issues. Some common deficiencies are:

a. Requirements validation - tested under ideal conditions (e.g. room temp, bench power supply).

b. Environmental (non EMC) testing mainly wear-out oriented.

c. EMC testing not realistic - room temp only, idealized noise signals.

d. System interactions, interfaces and degradation not sufficiently addressed.

This document addresses much of the above using relatively simple and low cost techniques which:

a. Requires minimal lab facilities.

b. Allows maximum flexibility to experiment early in the program.

c. Allows sufficient reaction time to react to potential issues.

d. Stage where failures are good (maximizes information).

One main issue addressed here is Conducted Immunity (CI). That aspect of Electromagnetic Compatibility (EMC) has the highest potential for warranty and customer satisfaction issues. However, traditional validation testing for CI has major limitations. Specifically, CI testing is most often run at room temperature due to the nature of the test equipment and facilities - the response of the product could be different when cold or hot than at room temperature. Another limitation is that very repeatable, accurate and idealized signals are used to represent the "real world". While this would appear to be desirable, it is not necessarily the case. The "real world" contains randomness and other characteristics (e.g. complex impedances) not replicated by such idealized test signals. Randomness is extremely critical for a microprocessor type DUT since the stress event (e.g. transients) must often line up in time with a certain point(s) in software execution to have an effect.

It is important to note that many of these tests are not the "test for success" type where the results are classified as either pass or fail. Such testing is of limited value since it generates little information. The goal is to generate variable data or anomalies so that the maximum amount of information is obtained and an informed engineering judgement can be made.

Customers who purchased SAE J2628
also purchased

• AATCC 124 : Smoothness Appearance of Fabrics after Repeated Home Laundering
• AATCC 130 : Soil Release: Oily Stain Release Method
• AATCC 132 : Colorfastness to Drycleaning
• AATCC 135 : Dimensional Changes of Fabrics after Home Laundering

See More Documents