OTA—C连续时间滤波器可编程问题研究

AN INVESTIGATION ON PROGRAMMABLE ISSUES OF OTA—C CONTINUOUS—TIME FILTERS

讨论OTA—C连续时间滤波器的数字化编程控制方法。提出用有源电容提升电路取代电容加权阵列,以扩大滤波器参数的调节范围;还提出相应的数字控制电路,并构成可编程低通滤波器的芯片电路框图;用双极型OTA及数字组件构成分离电路进行部分实验,提供了实验结果。

This paper discusses the digitally controlled method of OTA—C continuous time filters. To extend the controllable range of filter parameters, a method of using active capacitor multipliers to replace passive capacitor arrays was proposed. Digital circuit blocks and integrable block diagram of a programmable low-pass filter were presented. Experiments with the discrete circuit of the designed filter using bipolar OTAs have been made, and the experiment results are given.