Understanding Differential Probes

This video is a technical introduction to differential probes and when to use them instead of standard single-ended probes. Differential measurements are essential for applications like measuring voltages across power transistors and analyzing differential signaling protocols such as USB and CAN. The tutorial compares two measurement approaches: the quasi-differential method using two single-ended probes with math functions, versus dedicated differential probes with internal differential amplifiers. Key specifications unique to differential probes are explained, including Common Mode Rejection Ratio (CMRR), Differential Mode Range (DMR), and Common Mode Range (CMR). Safety considerations and practical tips like lead twisting for noise reduction are also covered.

What you’ll learn:

• The differences between single-ended and differential measurements, and why connecting a standard probe’s ground lead to non-ground points can cause damage or safety hazards
• How differential probes work using internal differential amplifiers to measure voltage between two points without requiring a ground reference, and their advantages over the quasi-differential two-probe approach
• Critical differential probe specifications including CMRR, differential mode range, and common mode range and how to recognize when these limits are being exceeded during measurements

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