This paper presents a controllable resistor, which is formed by a MOS-resistor working in the deep triangle region and an auxiliary circuit. The auxiliary circuit can generate the gate-source voltage which is proporti...This paper presents a controllable resistor, which is formed by a MOS-resistor working in the deep triangle region and an auxiliary circuit. The auxiliary circuit can generate the gate-source voltage which is proportional to the output current of an low dropout regulator for the MOS-resistor. Thus, the equivalent output resistance of the MOS-resistor is inversely proportional to the output current, which is a suitable feature for pole-zero tracking frequency compensation methods. By switching the type of the MOS-resistor and current direction through the auxiliary circuit, the controllable resistor can be suitable for different applications. Three pole-zero tracking frequency compensation methods based on a single Miller capacitor with hulling resistor, unit-gain compensation cell and pseudo-ESR （equivalent serial resistor of load capacitor） power stage have been realized by this controllable resistor. Their advantages and limitations are discussed and verified by simulation results.展开更多
针对超声波气体流量计接收信号幅度动态变化范围大的问题,提出了一种数控AGC电路,增益控制范围-14-86 d B,输出信号幅度范围500-1 000 m V,采样速率50 MSPS,数据存储容量2 MB。经过试验验证,200 k Hz的超声波收发信号在距离20-900 mm条...针对超声波气体流量计接收信号幅度动态变化范围大的问题,提出了一种数控AGC电路,增益控制范围-14-86 d B,输出信号幅度范围500-1 000 m V,采样速率50 MSPS,数据存储容量2 MB。经过试验验证,200 k Hz的超声波收发信号在距离20-900 mm条件下,增益在6-36 d B范围内自动调节实现了信号幅度范围500-1 000 m V输出,具有调控范围大、控制精度高、稳定性好的特点。展开更多
文摘该宽带放大器针对20 Hz^10 MHz信号进行放大的目的,采用前置放大电路、增益放大电路、末级大信号放大电路、单片机显示与控制电路和直流稳压电源五大部分构成宽带直流放大器。通过对电路进行最终的测试,整个系统可以实现在18 Hz^11 MHz的范围内放大增益在40 d B范围内可调,带内增益起伏小于1 d B。
基金Project supported by the Key Science and Technology Project of Zhejiang Province,China (No.2007C21021)
文摘This paper presents a controllable resistor, which is formed by a MOS-resistor working in the deep triangle region and an auxiliary circuit. The auxiliary circuit can generate the gate-source voltage which is proportional to the output current of an low dropout regulator for the MOS-resistor. Thus, the equivalent output resistance of the MOS-resistor is inversely proportional to the output current, which is a suitable feature for pole-zero tracking frequency compensation methods. By switching the type of the MOS-resistor and current direction through the auxiliary circuit, the controllable resistor can be suitable for different applications. Three pole-zero tracking frequency compensation methods based on a single Miller capacitor with hulling resistor, unit-gain compensation cell and pseudo-ESR （equivalent serial resistor of load capacitor） power stage have been realized by this controllable resistor. Their advantages and limitations are discussed and verified by simulation results.
文摘针对超声波气体流量计接收信号幅度动态变化范围大的问题,提出了一种数控AGC电路,增益控制范围-14-86 d B,输出信号幅度范围500-1 000 m V,采样速率50 MSPS,数据存储容量2 MB。经过试验验证,200 k Hz的超声波收发信号在距离20-900 mm条件下,增益在6-36 d B范围内自动调节实现了信号幅度范围500-1 000 m V输出,具有调控范围大、控制精度高、稳定性好的特点。
