《示波器探测需要避免的七大常见错误》.pdf

TAKE THE MYSTERY OUT OF PROBING 7 Common Oscilloscope Probing Pitfalls to Avoid Introduction Understanding common probing pitfalls and how to avoid them is crucial in making better measurements. In an ideal world, all probes would be a non-intrusive wire attached to your circuit having infinite input resistance with zero capacitance and inductance. It would provide an exact replica of the signal being measured. But the reality is that probes introduce loading to the circuit. The resistive, capacitive, and inductive components on the probe can change the response of the circuit under test. Every circuit is different and has its own set of electrical characteristics. Therefore, every time you probe your device, you want to consider the characteristics of the probe and choose one that will have the smallest impact to the measurement. This includes everything from the connection to the oscilloscope input down through the cable to the very point of connection on the DUT, including any accessories or additional wiring and soldering used to connect to the test point. Learn about pitfalls you might be making in your tests and how your measurements can be improved with better practices. The electrical behavior of your probe affects both your measurement results and the operation of your circuitry. Taking action to ensure these effects are within acceptable limits is a key step to successful measurements. Contents 7 Common Oscilloscope Probing Pitfalls to Avoid Not Calibrating Increasing Probe Not Fully Utilizing Your Selecting the Wrong Your Probe Loading Differential Probe Current Probe Uncalibrated probes give distorted All probes will load your circuit to some extent. Your differential