Design of the Programmable Gain Filter

Using single chip microcomputer as the system control center, compose of controllable amplifier, programmable filter and amplitude-frequency characteristics of the test parts. Realizing the input signal gain control by voltage gain adjustable, adopt switched capacitor technology realize the programmable filtration, the choice of DDS technology generate sweep signal; all the basic requirements and play part of the requirements in the title are achieved. In addition, we have expanded the band-pass filter, realized the storage and display of amplitude-frequency characteristic curves. It is using the menu function selection mode, and user-friendly human-computer interaction. A circuit of high integration is helpful to reduce cost and power consumption.