Modeling and Simulation of a Compensation PCB for Oscilloscope Probes

This paper describes and demonstrates the way of realizing a compensation PCB for the oscilloscope probes. The compensation PCB is helping one person to use the probe at different attenuation values as 1:1 or 10:1. The paper analyses the actual available circuits, a block-diagram of the compensation probe and where it is placed in a complete test system. Nevertheless, the simulation and results obtained with the help of LTSpice software are presented. The problem shown and solved in the paper is coming from the necessity of having a long oscilloscope cable (3 meters long) connected directly to a Device Under Test (DUT). The problem is showing up much more frequently in the last period of time in the automotive industry due to the needs of testing and validating different new Integrated Circuits (IC’s) and electronic components in climate chambers, which does not allow one to introduce all the test equipment inside, but only the DUT and the probes. This circuit intends to help the user to obtain voltage measurement results with noise (which is coming from the cable length) cancelation and to compensate the wrong amplitude of the signal and also to eliminate the frequency disturbance caused also by the cable length. Beside the circuit, the paper presents also the models that were realized and the obtained results.