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  • Author Author: mlease
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Accurate low-current measurements with a scope

mlease

Last week was incredibly busy so I wasn’t able to put the time in to complete the third part of the “Leakage currents & current leaks” post. This will be a short post with a link to a white paper on our website for more details.

 

Most engineers consider the oscilloscope their first tool of choice for hardware development work. Yet very few engineers ever consider how accurate their scope is. Most of the major oscilloscope manufacturers place great importance on the timing aspects of their products. Multi-gigahertz sample rates are fairly common today in mid-range digital scopes today yet most of those scopes only have 8-bit A/D converters. While timing accuracy is often spec’d in double-digit ppm, voltage measurement error on the same scope can be as much as the signal level you need to measure using a scope’s lowest volts/division setting.

 

Read the complete post at http://cmicrotek.com/wordpress_159256135/.

  • Good points. Part of understanding your test equipment is knowing the conditions the specs apply for. It is fairly common even for modern-day scopes to specify a 30 minute warm-up in order to meet performance specs. That isn't so much of a problem as it is something an engineer must be aware of in order to get the most accurate measurements possible. Up-to-date calibration is also critical to getting measurements you can believe.

  • Good post.

     

    As I continue to explore charge flow at the atomic level I am finding many useful ideas on how to prove both my theories and how to really understand what goes on inside electronic components.

    Learning good accuracy techniques is a great skill to have.

    I got into it early working in a laboratory doing cutting edge research into the effects of lasers on optics.

    We had many issues that we had to define so that we could assess what we had learned from each experiment.

    I still carry those skills today, some forty years later.

     

    Understanding your test equipment is every bit as important as your design and build.

    You need to verify every performance issues to rule out the possibility that you are seeing a measurement artifact verses an actual signal result.

     

    DAB

  • So true. We concentrate on speed and not on accuracy.

    Clem