Design of Input Overvoltage Protection Circuit of Operational Amplifier Composed of JFET
In order to make up for the defects of the traditional input overvoltage protection circuit of operational amplifier,a new input overvoltage protection circuit is designed.The circuit is designed by Analog Foundries's 4 μm bipolar process,which is mainly composed of JFET and clamping diode.The overvoltage current is finally saturated by using the principle of JFET channel pinch-off,and the overvol-tage protection function is realized.Symmetry design is adopted to make the saturation overvoltage current equal under positive and negative overvoltage.The simulation results show that the input overvoltage protection circuit of the operational amplifier has less noise than the traditional structure,has a stronger limiting effect on overvoltage current,and has certain application value.
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维普
