What parameters have you measured with an oscilloscope?

The oscilloscope is the most common instrument for electronic engineers. Many people also compare the oscilloscope to the "eyes" of engineers, which is enough to show how important the oscilloscope is to engineers.

How does a signal appear on an oscilloscope screen? On an oscilloscope, the signal travels through a series of resistors and capacitors inside the probe. Then entering the oscilloscope, the signal enters the oscilloscope and passes through the analog input signal modulation module. Depending on the size of the signal, it is amplified or reduced accordingly to fit within the dynamic range of the analog-to-digital converter (ADC). Analog signals are converted into digital data (1s and 0s) in the ADC module. At the same time, the trigger module compares the signal with the specified trigger condition. Trigger conditions tell the time base module when to capture digital data and save it to loop acquisition memory. A digital signal processing module (DSP) analyzes the digital data and reconstructs it into a waveform that is displayed on the screen.

For all oscilloscopes, after the signal is displayed on the oscilloscope, the next step is to perform the corresponding measurement. Oscilloscopes now have an extremely rich set of built-in measurement capabilities, allowing engineers to quickly analyze the amplitude and time parameters of waveforms. Examples of these basic measurements include:

Rise Time: The rise time is the time at the upper threshold minus the time at the lower threshold of the edge you are measuring. The fall time is similar, that is the time on the lower threshold minus the time on the upper threshold of the edge you are measuring.

Pulse Width: Pulse width is the time from the middle threshold of the first rising edge to the middle threshold of the next falling edge.

Amplitude and other voltage measurements: This is a measurement of the amplitude of the waveform display. Typically you can also measure peak-to-peak voltage, maximum voltage, minimum voltage, and average voltage.

Period/Frequency: Period is defined as the time between two consecutive crossover voltages of the intermediate threshold. Frequency is defined as 1/cycle.

Setup and hold time: Setup time is the minimum time that data needs to remain stable before the clock hits. The hold time is the minimum time that the data needs to remain stable after the clock trigger event arrives.

,

Eye diagram: The so-called eye diagram simply means superimposing a series of pulse signals (000,001,010,011, 100, 101,110,111) received by the receiving end on a high-speed oscilloscope at the same time to form an eye diagram. If you add an eye diagram template, you can quickly evaluate whether the signal can meet the bus requirements or system requirements. [Facts] The story behind the eye diagram [Bright Eyes] and [Waist Waist]

There are many other measurements on an oscilloscope, such as duty cycle, offset, noise, jitter, and more. Only some basic measurement concepts are provided here.

Traditionally, the parameters measured by oscilloscopes are in the time domain. However, with the development of technology, oscilloscopes have also become diversified. Some oscilloscopes can also measure parameters in the frequency domain, especially in power integrity and EMC analysis. The time domain signal will be converted into a frequency domain curve for analysis. Observe which frequency band has the problem, and then "prescribe the right medicine" to solve the problem.

No matter what, the oscilloscope is always just a tool. To analyze the actual problem, engineers need to be able to find the essence through the phenomenon.