低失调电压低输入噪声仪表放大器设计

Design of Instrument Amplifier with Low Offset Voltage and Low Input Noise

仪表放大器具有低失调电压、低噪声等优点,被广泛应用于工业仪表、航空航天等领域中,具有广泛的应用前景。采用华虹BCD350GE工艺设计一种低失调电压低输入噪声仪表放大器。该仪表放大器采用三运放、双输入双输出结构。电阻使用开关控制使得增益可控。采用斩波技术来减小失调电压和输入噪声。在全工艺角下进行失配分析,并进行输入噪声的仿真。应用Cadence工具进行设计仿真,结果表明其具有较低的失调电压和等效输入噪声,并能实现增益可控。实验结果证明了该仪表放大器在仪器仪表中的适用性。

Instrumentation amplifier has the advantages of low offset voltage and low noise. It iswidely used in industrial instruments, aerospace and other fields and has a wide application prospect. Alow offset voltage and low input noise instrument amplifier is designed using Huahong BCD350GEtechnology. The instrument amplifier adopts three operational amplifiers and two-input and two-outputstructures. The resistor uses switch control to make the gain controllable. Chopper technique is used toreduce offset voltage and input noise. Mismatch analysis is carried out at the full process angle and inputnoise simulation is carried out. The Cadence tool is used for design simulation, and the results show thatit has lower offset voltage and equivalent input noise, and can achieve controllable gain. The experimentalresults prove the applicability of the instrument amplifier in the instrument.