An integrated low 1/f noise and high-sensitivity CMOS instrumentation amplifier for TMR sensors

作者：Gao, Zhiqiang^*; Luan, Bo; Zhao, Jincai; Liu, Xiaowei

来源：Modern Physics Letters B, 2017, 31(8): 1750070.

DOI：10.1142/S0217984917500701

• Magnetic tunnel junction
• Wheatstone bridge
• application specific integrated circuit
• instrumentation amplifier
• 1/f noise

In this paper, a very low 1/f noise integrated Wheatstone bridge magnetoresistive sensor ASIC based on magnetic tunnel junction (MTJ) technology is presented for high sensitivity measurements. The present CMOS instrumentation amplifier employs the gain-boost folded-cascode structure based on the capacitive-feedback chopper-stabilized technique. By chopping both the input and the output of the amplifier, combined with MTJ magnetoresistive sensitive elements, a noise equivalent magnetoresistance 1 nT/Hz(1/2) at 2 Hz, the equivalent input noise spectral density 17 nV/Hz1/2(2Hz) is achieved. The chip-scale package of the TMR sensor and the instrumentation amplifier is only about 5 mm x 5 mm x 1 mm, while the whole DC current dissipates only 2 mA.

• 出版日期2017-3-20
• 单位哈尔滨工业大学