集成双极性神经刺激脉冲发生器设计

Design of integrated bipolar nerve stimulation pulse generator

基于SMIC 0.18μm CMOS工艺,设计了一种幅度、频率、占空比可调的集成双极性神经刺激脉冲发生器。利用带隙基准电流源产生基准电流,通过两级电流镜级联将电流复制和放大以实现幅度范围可调。采用脉冲宽度调制(PWM)信号控制H桥开关管的通断实现频率、占空比可调的双极性信号。利用Cadence仿真软件,对电路进行了仿真。结果表明:当电源电压为5 V,在-40~100℃下,基准电流温漂系数为5.38×10^(-6)/℃;系统可产生幅度为0.01~10 mA,频率为1 Hz~2 kHz,脉冲宽度为20~1 000μs范围内可调的双极性脉冲信号。

A bipolar pulse generator with adjustable amplitude, frequency and duty cycle is designed for nerve stimulation, based on a SMIC 0.18 μm CMOS technology, a bandgap reference current source is exploited to generate the reference current, and it is duplicated, magnified and superimposed by two stage current mirrors in cascaded to achieve adjustment in range of amplitude.Pulse width modulation(PWM)signals are applied to control the on-off of H-bridge switch and realize bipolar signal with adjustable frequency and duty cycle.The circuit is simulated by Cadence.The results show that when the power supply voltage is 5 V,the temperature drift coefficient of the reference current is 5.38×10^(-6)/℃ at-40~100 ℃,and the parameters of the generated bipolar pulse are adjustable within an amplitude range of 0.01~10 mA,a frequency range of 1 Hz~2 kHz and a pulse width range of 20~1 000 μs.