一种自旋阀GMR隔离放大器设计

为了解决传统光电隔离、电容隔离和变压器隔离存在的线性度及频率特性等问题，设计了一种自旋阀巨磁阻（GMR）隔离放大器，具有灵敏度高、线性度好及结构简单等特点，且可以与硅等半导体电路集成。基于CSMC 0.5μm混合信号工艺，采用Tanner软件对电路进行编辑、仿真与验证。隔离器前端电路可将0～5 V的输入电压转换为1.4～10 mA电流，后端接收电路在增益为1时的共模抑制比为73 dB，增益可调节范围为1～200，工作带宽大于100 kHz，能满足恶劣环境条件下应用的各项指标要求。

Design of a spin-valve GMR isolation amplifier

In order to solve the linearity and frequency characteristic problems existing in the isolator for traditional photo-electric,capacitance and transformer isolation,a spin-valve giant magneto-resistance （GMR） isolation amplifier is designed, which can be integrated together with the silicon semiconductor,and has the characteristics of high sensitivity,well linearity, simple structure,etc. The Tanner software is used to edit,simulate and verify the circuit with the CSMC 0.5 μH double poly mix process. The front-end circuit of isolator transforms 0~5 V input voltage into 1.4~10 mA output current,and when the gain is 1,the back-end receiving circuit CMRR is 73 dB,the gain adjustable range is 1~200,and operating bandwidth is more than 100 kHz. The amplifier can meet the design requirements used in abominable environment.