Low Pass Filter 4th Order Butterworth Switched Capacitor Cutoff Frequency Single Resistance Adjustable | Бытовая техника

Low Pass Filter 4th Order Butterworth Switched Capacitor Cutoff Frequency Single Resistance Adjustable | Бытовая техника

Ling Zhi Electronics

Switched Capacitor Low Pass Filter ModuleV1.0

1 Module introduction

General traditional analog filters are changed by changingRLCFrequency response characteristics of discrete element parameter-changing filters，Its parameter adjustment is more troublesome.，And this kind of filter can only achieve fixed cut-off frequency filtering function.。Switched Capacitor Filter（Switch Capacitor Filter，Abbreviated asSCF）Using Sampling System to Approximate the Characteristics of Analog Continuous Filter。Central or Cut-off Frequencies of Switched Capacitor Filters and an External Clock Input Signal（Sampling clock）Relevant，The center frequency or cut-off frequency of the filter can be changed by adjusting the frequency of the clock input signal.。This module can easily change the cut-off frequency through a potentiometer.，Convenient and easy to use。

The main features of the module are as follows：

（1）Whole plate characteristics：The filter type isFourth-order Butterworth low-pass filter，Cut-off frequency of filterAdjustable，Gain is0dB（1times），Peak-to-Peak Range of Signal Input50mVpp ~ 7Vpp。

（2）Cut-off Frequency Adjustment Range：2.6Hz~26kHz。Just go through the moduleA potentiometerchangecut-off frequency。2frequency doublingThe attenuation is24dB（0.06times）About，10frequency doublingThe attenuation is80dBAbout。The ripple fluctuation in passband is very small。

（3）Module power supply：Module usage±5Vpower supply。

（4）Module adoption±5Vpower supply。

（5）Input and output interfaces take two forms，One is the pin interface.（defaultmode），One isSMAInterface（Reserve）。

（6）This module designs the jack.GND，Grounding Pen for Plugging Multimeter，To facilitate user testing。

2 Module interface

Schematic diagram of module interface

3 Module Interface Connection Method

Module debugging connections are shown in the following figure：

Diagram of Module Debugging Connection

4 Module debugging effect

The filter cut-off frequency is given below.1kHz、Peak and Peak of Input Signal1VppModule Amplitude-Frequency Characteristic Curve in Case：

The waveforms of the test part are as follows：

input700Hz@1Vpp，Output waveform

input1kHz@1Vpp，Output waveform

input2KHz@1Vpp，Output waveform