高灵敏度的CMOS霍尔磁场传感器芯片设计

以霍尔电压及失调电压的状态为出发点,提出了一种更简单的霍尔信号再生电路设计方案.即采用由传输门、保持电容和电压跟随器构成的采样保持电路实现对混叠信号(包括霍尔信号和失调电压)180°移相,再经相减电路去除失调电压.后仿真结果表明该芯片工作在2.5～3.3 V电压下,能对0.1 mV的霍尔信号进行1 500倍放大并输出CMOS数字信号,可允许的最大失调电压为4 mV.

Design of High Sensitive CMOS Monolithic Magnetic Hall Sensor

Based on analyzing the status of hall and offset voltage, a completely new and comparatively simple hall signal regeneration circuit was brought forward. That is, using a sampling and holding (S/H) circuit which composes of a transmission gate, a holding capacitance and a voltage follower to shift the 180° phase of the mix signals(contains the hall and offset voltage). Subsequently, the mix signals input a subtraction circuit to be wiped off the offset voltage. The post layout simulation results show that it can amplify minimum 0.1 mV input hall signal with 1 500 amplification factor and output CMOS digital signal is from 2.5 to 3.3 V working voltage. The tolerable input maximum offset voltage is up to 4 mV.