Design And Simulation Of The Low-noise Amplifier For1/f Low-frequency Electrical Noise

1/f noise is the key factor of evaluation of semiconductor’s technical qualityand service life. Low-noise amplifier is vital because1/f noise is extremely weak. Inorder to detect1/f noise and reduce background noise to maximum degree, the designof low-frequency low-noise amplifier is necessary. So far,1/f noise detection systemof proplus Electronics’9812D have the performance of high-end,because a pluralityof testing system of low-noise amplifier for voltage and current were equipped in it sothat it can make sure of the most accurate for different devices and testingconditions.Based on a series of MAX412low-noise amplifier chips andinstrumentation amplifier architecture,this paper gives design and analysis oflow-noise amplifier for1/f low-frequency electrical noise.Firstly,the thesis has summarized the present situation in the field of low-noiseamplify for low-frequency at home and abroad.And then,the characteristics of1/flow-frequency electrical noise are analyzed and the type of amplifier are determined.Then this paper analysis parameters of MAX412chip comprehensively,including voltage noise density, equivalent input noise, temperature characteristic,impedance characteristics, and establishes noise analysis model for each individualmodules,which is used to compare with LT1028low-noise amplifier chip in common,highlighting its superiority for amplify low-frequency signal.Finally, according to the need of amplifier module, Ferris formula as thetheoretical basis,and with the use and improvement of the differential inputstructure,this paper selects N-JFET of IFN152as the main semiconductor devices andequips with pre-amplifier circuit of excellent noise performance.This paper describes a complete circuit’s design process, analyses andcalculates the parameters for each component in detail and completes schematicdesign comprehensive simulation, the simulation results of the data analysis anddiscuss the outcome.The result is: the design of the amplifier with high gain and low noisecharacteristics at1Hz-100kHz, with low equivalent input noise1.12nV/√Hz at10Hz, the noise coefficient of1.80dB.