低压高速大驱动电流BiCMOS模拟开关单元

从改善速度和电流驱动能力出发,设计了4种BiCMOS模拟开关电路。设计过程中在电路的关键部位配置有限的双极型晶体管(BJT),而在电路的主体部分则设置CMOS器件。推导出电路的传延时间估算式,优选了元器件参数,并采取提速和增大驱动电流的措施。实验结果表明,所设计的BiCMOS开关电路在低电源电压2.6V≤VDD≤4.0V的范围内,综合性能指标——延迟-功耗积DP比CMOS开关电路平均降低了36.52pJ,输出级BJT的驱动电流可达1.40mA以上,因而特别适用于低压、高速、大驱动电流的数字通信系统中。

Low-voltage,High-speed and Large-drive-current BiCMOS Analog Switch Cells

For improving their speed and drive ability,4 kinds of BiCMOS analog switch cells were designed. A few of BJTs were set on the key parts,but CMOS devices were put on the main circuit. Several delay-time formulae were deduced and optimum parameters of the BJT and MOS devices were selected,and some technologies and measures were also adopted in the course of the design. The related analysis,simulations and experimental results show that the designed BiCMOS switch cells work properly within 2.6 V～4.0 V,and the delay-power product(DP) is reduced by an average of 36.52 pJ,and their drive current even reaches more than 1.40 mA as compared with that of the conventional CMOS cell. With these characteristics the designed BiCMOS switch cells are very suitable for low-voltage,high-speed and large-drive-current digital communication system.