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Basics of Oscilloscopes. Presenter Name Presentation Name 1. Agenda. What Is an Oscilloscope Why Do We Use an Oscilloscope 4 Key Technical Aspects of Oscilloscopes You Should Know About. What is an Oscilloscope?. A MultiMeter displays discreet measurements.
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Basics of Oscilloscopes Presenter Name Presentation Name 1
Agenda • What Is an Oscilloscope • Why Do We Use an Oscilloscope • 4 Key Technical Aspects of Oscilloscopes You Should Know About.
What is an Oscilloscope? • A MultiMeter displays discreet measurements. • In a multimeter, the unknown quantity is sampled and converted to a known relative value at a rate of approximately 3-4 times per second. Volts Time
Volts Time What is an Oscilloscope? • An oscilloscope graphically plots the unknown quantity over time. “A picture is worth a thousand words!”
Why Do We Use an Oscilloscope • Analyze the integrity of waveforms • Sine • Square • Triangle • Ramp • DC
Why Do We Use an Oscilloscope • Looking for common anomalies • Noise • Glitch • Ringing • Jitter
Why Do We Use an Oscilloscope • Making common measurements • Voltage • Horizontal Time • Delta Time • Rise or Fall Time
Why Do We Use an Oscilloscope • Making Automatically calculated measurements • Frequency • Phase • Duty Cycle • dB Level • Power
Why Do We Use an Oscilloscope • Perform Waveform Mathematics • A vs B (XY or Lissajous) • A x B • A + B • A - B
Key Technical Aspects: 1) Sample Rate & Bandwidth • Sample Rate • Sample Rate • Time • An unknown signal is segmented in time. The voltage of the signal at each time segment is determined. This voltage value is stored to internal memory.
Key Technical Aspects: 1) Sample Rate & Bandwidth • Bandwidth = Maximum captured frequency, and is dependant on; • The Scope’s input circuit (The max frequency where the amplitude starts to decrease by more than -3dB.) • Enough samples in order to accurately resolve and display a signal. Typically you need 10 samples per period. • Too Few samples Results In… • An in-accurate representation of the true waveform (Aliasing)
Key Technical Aspects: 2) Memory • The amount of memory will effect the sample rate! • Consider: A sine wave of 1 second period. Sampled at a rate of 1 GSa/S (1 billion), how much memory will the Oscilloscope need?
Key Technical Aspects: 3) Triggering • Trigger is used to synchronize the waveform display at each display update/refresh. • It can also be used to capture specific “events”
Key Technical Aspects: 3) Advanced Functions • ScopeRecord: Is used to look at a long term trend using high resolution waveform capture. • View All mode shows the “trend” • “Zoom in” to look at the individual cycles
Key Technical Aspects: 3) Advanced Functions • Replay: Automatically capture the last 100 screen updates. Go back in time to look at intermittent events or anomalies. “Its like having a video recorder capturing an event, press rewind to see what really happened!”
Oscilloscopes? • An oscilloscope is the engineers view into electronic/electrical signals. • It’s the best tool for troubleshooting signal anomalies or intermittent failures. “If you cannot see it, you cannot fix it”