8 Reference

Digital channel signal fidelity: Probe impedance and grounding

You may encounter problems when using the mixed-signal oscilloscope that are related to probing. These problems fall into two categories: probe loading and probe grounding. Probe loading problems generally affect the circuit under test, while probe grounding problems affect the accuracy of the data to the measurement instrument. The design of the probes minimizes the first problem, while the second is easily addressed by good probing practices.

Input Impedance

The logic probes are passive probes, which offer high input impedance and high bandwidths. They usually provide some attenuation of the signal to the oscilloscope, typically 20 dB.

Passive probe input impedance is generally specified in terms of a parallel capacitance and resistance. The resistance is the sum of the tip resistor value and the input resistance of the test instrument (see the following figure). The capacitance is the series combination of the tip compensating capacitor and the cable, plus instrument capacitance in parallel with the stray tip capacitance to ground. While this results in an input impedance specification that is an accurate model for DC and low frequencies, the high-frequency model of the probe input is more useful (see the following figure). This high-frequency model takes into account pure tip capacitance to ground as well as series tip resistance, and the cable’s characteristic impedance (Zo).

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6000 Series Oscilloscope User’s Guide

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Agilent Technologies 6000 Series manual Input Impedance
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6000 Series specifications

Agilent Technologies has long been recognized as a leader in the field of electronic measurement and test equipment, and the Agilent 6000 Series oscilloscopes exemplify this commitment to innovation and quality. Designed for both professional engineers and researchers, the 6000 Series offers a comprehensive suite of features that enhance usability, accuracy, and efficiency in various applications.

At the heart of the Agilent 6000 Series is its advanced architecture, which integrates a high-performance analog-to-digital converter (ADC) and a sophisticated digital signal processing engine. This combination enables users to capture fast, high-resolution signals with remarkable accuracy, making it suitable for a wide range of applications, from automotive to telecommunications.

One of the standout features of the 6000 Series is its bandwidth options, which typically range from 100 MHz to 500 MHz. This flexibility allows users to select an oscilloscope that best fits their specific needs. Coupled with a sampling rate of up to 4 GSa/s, the 6000 Series offers exceptional timing resolution, ensuring that even the most fleeting signals are accurately represented.

The user interface of the 6000 Series is designed for maximum efficiency. The oscilloscopes are equipped with a large, high-resolution display, enabling users to view complex waveforms in detail. Furthermore, the touch screen interface provides a level of interactivity that simplifies navigation through various functions, making it accessible for both seasoned professionals and novices alike.

Additionally, the 6000 Series incorporates advanced triggering capabilities, allowing users to isolate specific events in their signals easily. The wide array of available triggering options includes edge, pulse width, and serial triggering formats, which are vital for analyzing complex digital communications.

Another noteworthy characteristic of the Agilent 6000 Series is its built-in measurement and analysis tools. The oscilloscopes come equipped with automated measurements, enabling users to quickly gather important data about their signals without manual calculations. This reduces the time spent on testing and increases overall productivity.

In terms of connectivity, the 6000 Series includes USB and LAN interfaces, providing easy data transfer and integration with other devices. The inclusion of advanced software options further enhances data analysis capabilities, enabling users to perform extensive post-acquisition analysis.

In summary, Agilent Technologies' 6000 Series oscilloscopes represent a blend of cutting-edge features, user-friendly design, and high-performance technologies, making them an invaluable tool for engineers and scientists engaged in electronic measurements and analysis. Their versatility and power make them well-suited to meet the demands of modern engineering challenges.
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