Single current bias circuit of a current source, which is characterized in that the bias circuit comprises a plurality of connected MOS tubes in two adjacent MOS tubes, a MOS tube source and another MOS tube drain is located at the top of the MOS tube is connected with the constant drain current source, gate MOS pipe at the top of the adjacent phase and after MOS tube is connected to the constant current source, located on the bottom of the MOS tube source public access terminal, the gate of the MOS transistor is connected to the adjacent MOS tube drain, and the lower end of the gate tube adjacent to the MOS MOS the tube is connected to the top of the MOS tube source, at the same time, adjacent and at the top of the MOS tube, MOS tube as the output tube, the drain source bias circuit as output.
【技术实现步骤摘要】
本专利技术涉及基于MOS元件的Cascode模拟电流源,更具体地指一种电流源的单电流偏置电路。
技术介绍
在模拟电子电路中广泛采用电流源为模拟电流电压信号的传递媒介。衡量电流源性能的指标包括电流源的输出阻抗、输出节点电压动态范围和电流跟踪特性等。由于Cascode电流源能够提供非常高的输出阻抗和良好的电流跟踪特性而受到了广泛的应用,但是它的输出节点的电压动态范围受限于Cascode电流源结构的偏置电压,因此需要正确地偏置Cascode电流源来提高它的输出节点电压动态范围。图1给出了一种最简单的Cascode电流源的偏置电路,因为它的简单,使得它得到了非常广泛的应用,该偏置电路的缺点是输出节点的电压动态范围较小。在这种Cascode电流源中,输出节点N2的最小电压为VN2(min)=Vgs3+Vgs4-Vth=Vgs3+Vdsat4=Vdsat3+Vdsat4+Vth3图2给出了另一种Cascode电流源的偏置电路,如果N4点的电压为M1的Vdsat1,那么M5的栅电压Vg5=Vdsat1+Vgs5。如果M2和M6的宽长比相等,则Vgs2=Vgs6,所以VN2的 ...
【技术保护点】
【技术特征摘要】
【专利技术属性】
技术研发人员:刘家洲,
申请(专利权)人:上海贝岭股份有限公司,
类型:发明
国别省市:
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