Step 1: select or choose required cutoff frequency. Suppose we want to pass all the frequencies below 15 KHz that means frequencies that human can hear. So fc = 15000 hzStep 2: assume the required value of capacitor. It should be less than 0.1 micro Farad. This is required for better frequency stability. Suppose we assume C as 4.7 nF (nano farad)Step 3: calculate the value of resistance from equation.. 

To avoid unwanted noise in the output, a filter is required to be placed before it. Such filters are more commonly used in audio circuits. To avoid or retain [[wysiwyg_imageupload::]]frequencies which are higher than filter’s cutoff frequency, a low pass filter is employed. The low pass filter circuit which is the prime part of this project, filters a frequency spectrum or any mix of frequencies. It is also known as high-cut filter since it provides a difficult passage to high frequency signals from source to output as shown in this project. Low pass filter is used for signal decoding, audio amplifiers, and demodulators. Also, various consumer electronic gadgets like mobiles, speakers system, gaming consoles, digital image display units apply a low pass filter.