Design of a spin-valve GMR isolation amplifier
Yang Rong-we · Modern Electronics Technique · 2013
In order to solve the linearity and frequency characteristic problems existing in the isolator for traditional photoelectric,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.