A Low Noise Low Power Chopper Amplifier Used For Filter

In the recent years,as low power becomes popular in circuit design,how to decrease the supply voltage becomes the research hotspot.However the reduction of supply voltage has a negative influence on dynamic and power dissipation.It is shown that low power is not only low voltage but also better circuit structure,low noise and offset. To improve the spec of the circuit can make the negative influence as low as possible when the supply voltage is decreased.According to the disscusion above,we study a chopperamplifier.We use the chop symbol to decrease the flicker noise and offset of the circuit and keep the dynamic range stable with low supply voltage.So it can work more stably.The amplifier is designed with full custom design approach.passing through circuit design ,circuit simulation,layout design,layout validation and post layout simulation.The results of simulation show that the SNR is for the sin input signal with 500uv amplititude and 10kHz frequency and the output loading capacitance of 100pf.The the DC open-loop gain ,the phase margin , and the unit gain band achieve 73dB, 81°and10MHz.In the thesis ,I talk about the idea of our design in the first chapter, introduce the source and model of the noise and how it can influence the power dissipasion in the second chapter,discuss the theory and design method of chop symbol in the third chapter,introduce the whole structure of the amplifier and characteristic of my design and the simulation and layout design in the fifth and sixth chapter.And we point out the merits and shortages of the design in the summary at last.