An active protection circuit for large dynamic range oscilloscope input channel

Abstract

The invention relates to an input channel active protection circuit for a large dynamic range oscilloscope. An input signal is connected to the input end of an input impedance matching module or the input end of an input impedance matching and power attenuation module, and the input ends of a plurality of operational amplification modules are respectively connected with the output end of the input impedance matching module or the output end of an input impedance matching and power attenuation module. The output ends of the plurality of operational amplification modules are respectively connected with an input end of a load sharing module, and the output end of the load sharing module is connected with an output signal. A bias adjusting module is disposed before the plurality of operational amplification modules. The bias adjusting module comprises an adjustable resistor, a current limiting resistor and an input impedance resistor, wherein the adjustable resistor, the current limiting resistor and the input impedance resistor are connected sequentially. The other end of the adjustable resistor is connected with a positive voltage or a negative voltage, and the other end of the input impedance resistor is grounded. The circuit irons out the defects in the prior art that signal reflection, caused by impedance mismatching, of a passive device (diode) cannot achieve the protection of a negative input signal at a protection moment, and the driving capability is weak.

Description

technical field [0001] The invention belongs to the field of electronic information engineering, and in particular relates to an active protection circuit for an input channel of an oscilloscope with a large dynamic range. Background technique [0002] In the measurement of fast pulsed ray signals, the dynamic range of the signal amplitude reaches more than 8 orders of magnitude. When using an oscilloscope to measure, it is necessary to use the method of range overlapping to realize signal integrity measurement. [0003] When measuring a pulse signal with a large dynamic range, when the range of the oscilloscope is much smaller than the amplitude of the input signal, the channel of the oscilloscope is easily damaged if the oscilloscope is not protected. To protect the oscilloscope channel, a 1:1 oscilloscope channel protector is required. [0004] The oscilloscope channel protector needs to meet the following conditions: high input bandwidth, input DC coupling, input imped...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide an active protection circuit for the input channel of an oscilloscope with a large dynamic range, which is used to solve the signal reflection caused by the impedance mismatch of the passive device (diode) in the prior art at the moment of protection. The negative input signal cannot be protected, and the driving ability is weak, etc.

Images