Analysis And Design Of CMOS Miller-Compensated Transconductance Amplifier

In recent years,with the rapid growth of IC demand,the design of analog integrated circuits has undergone tremendous changes.In addition to satisfying basic parameters,circuit design gradually has higher requirements for low power consumption,low noise,and high gain.In order to meet the low-power requirements of the circuit design,the circuit structure must adopt better frequency compensation technology.This kind of compensation method needs to reduce the energy consumption while also adapting to the topology of the low-voltage circuit.Therefore,in this paper,the operational amplifier of the general analog integrated circuit module is regarded as the research focus.Based on the application requirements of the sensor Wheatstone bridge interface circuit chip,the Wheatstone bridge weak signal amplification conditioning integrated circuit module is studied.According to the technical indicators of the Wheatstone bridge conditioning circuit,a CMOS transconductance operational amplifier with a secondary RC Miller compensation structure is used to realize the amplification and conditioning of the weak signal,and the sensor is provided with an integrated circuit CMOS detection interface.The CMOS Miller-compensated transconductance amplifier circuit is designed using a 0.18 um standard CMOS process,which is simulated and verified using the HSPICE tool.The research includes the following four aspects:(1)Common OTA(Operational Transconductance Amplifier)compensation structure design and its characteristics;(2)OTA performance parameters and the constraints of these parameters;(3)Design of CMOS operational amplifier circuit MOS transistor device according to the performance index;(4)CMOS operational amplifier simulation and layout verification.The simulation results show that CMOS circuit has a DC gain of 93 dB,a phase margin of 62.2°,a conversion rate of 30 V/?s,and an equivalent input thermal noise of 300 nV/Hz.The circuit has a unit gain bandwidth of 97.5MHz and a static power consumption of 2mW,meeting the design requirements.The amplifier uses a two-stage amplifier circuit to make the open-loop gain stable at a low frequency band,while having a large gain bandwidth and a good frequency characteristic,achieving a high performance index.The CMOS transconductance operational amplifier has the advantages of simple structure and good frequency compensation effect,so it has a certain engineering reference value.