A low-noise precision amplification circuit based on an operational amplifier and a performance improvement method thereof

The invention discloses a method for improving the performance of a low-noise precision amplification circuit based on an operational amplifier, which comprises the following steps: firstly, acquiringthe impedance of a signal source in an application scene and the output noise, total harmonic distortion and noise of a circuit needing to be improved, and determining the numerical value of a gain control potentiometer and the amplification gain of the circuit; Selecting a preset gain to adjust the original value of the potentiometer according to the signal source impedance; Then selecting the parallel connection number n of the buffer and cascade reverse amplification circuits and determining potentiometers; Selecting the number of resistor units; And finally, performing calculating according to the gain of the operational amplifier circuit, adjusting the value of a potentiometer and preset output impedance in combination with a preset gain, and adding a circuit adaptive part which is matched with the buffer an