添加数字调整到连续时间筛选器

摘要：这个设计备注显示如何添加的数模转换器（Dac）提供数字调谐到连续时间筛选器。双重过滤、双运算放大器和双通道DAC20kHz中心频率范围5To上形成不断的500Hz通可调带通电路。在这个设计中精选了MAX275连续时间筛选器和MAX412运算放大器。

Maxim>AppNotes>FilterCircuits(Analog)Keywords:filters,switched-capacitorfilters,continuous-timefiltersJul09,1998APPLICATIONNOTE63AddDigitalAdjustmenttoContinuous-TimeFiltersAbstract:Thisdesignnoteshowshowaddingdigital-to-analogconverters(DACs)providesdigitaltuningtocontinuous-timefilters.Adualfilter,dualopamp,anddualDACformanadjustablebandpasscircuitwithaconstant500Hzbandpassoverthe5kHzto20kHzcenter-frequencyrange.TheMAX275continuous-timefilterandMAX412opamparefeaturedinthisdesign.Tuned-bandpassapplicationsoftenincorporateswitched-capacitorfilters―thesefiltersenableasweepofthebandpasscenterfrequencybysimplysw