Probe interface circuit and probe adaptation circuit for probe of oscilloscope

Abstract

A probe interface circuit and a probe adapter circuit for a probe of an oscilloscope, wherein the probe comprises a probe interface circuit and a probe front end circuit, and the probe interface circuit comprises a control circuit, a detection circuit and a coaxial transmission circuit; the probe interface circuit is used for receiving a control signal generated by the oscilloscope from a communication interface of the oscilloscope, performing DC bias configuration according to the control signal to generate a bias configuration signal, and outputting a bias configuration signal to a probe front-end circuit through the output end of the bias circuit, so that the probe front-end circuit performs direct-current bias superposition on the signal to be detected under the action of the bias configuration signal, and generates a coaxial signal with output impedance matched with a BNC interface of the oscilloscope through attenuation adjustment and impedance adjustment. Because the probe interface circuit can generate the bias configuration signal according to the control signal, the free superposition of the direct current bias of the signal to be detected can be realized, and the functional defects of the existing oscilloscope probe can be overcome.

Description

technical field [0001] The invention relates to the technical field of oscilloscopes, in particular to a probe interface circuit and a probe adaptation circuit for a probe of an oscilloscope. Background technique [0002] An oscilloscope probe is a device that connects the signal under test to the input of the oscilloscope. Its performance is crucial to the accuracy and correctness of the measurement results. It is essentially an electronic component that connects the circuit under test to the input of the oscilloscope. The simplest probe is a wire connecting the circuit under test and the input end of the electronic oscilloscope. Since no shielding measures are taken, it is easy to be interfered by the external electromagnetic field, and its equivalent capacitance is large, which will easily increase the load of the circuit under test; however, Complex probes consist of RC elements and active devices. Oscilloscope probes can generally be divided into active probes and pass...

AI Technical Summary

Problems solved by technology

However, there are still some problems when using this circuit for probe adaptation connection: (1) The bias signal is directly connected to the active probe through the connector on the oscilloscope, so that the transmission process of the bias signal is exposed to the environment, and it is vulnerable to environmental electromagnetic interference. interference; (2) Both active probe identification and passive probe identification are identified through high level and low level, which limits the types of identifiable probes and is not conducive to the need for extended identification; (3) using a The 9-pin connector increases the risk of poor contact of the connector

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