Desinging an Amplifier

Using 3xTL072 and 2x MC33078 op amp chips, I designed an amplifier which had to meet rigorous criteria that mainly included:

-A passband between 1kHz – 100kHz with a gain of 100-103dB.

-Stop band frequencies of 100Hz and 1MHz where beyond this the frequency must drop below 40dB.

-An input impedance of 100ohms.

-Stop band frequencies of 100Hz and 1MHz where beyond this the frequency must drop below 40dB.

This was a challenging yet exciting experience where I began to learn critical information on how construction quality could heavily affect the function of circuits in the real world and it taught me how to select appropriate op amps based on their GBW, slew rate and other information available on datasheets.

Additionally, this was a useful introduction to 4th order Butterworth filters which I used to obtain the required passband criteria and how cascading these passive filters at different stages in the op amp could have a significant difference on the frequency response of the amplifier; hence, bringing forth the use of buffers to isolate different stages from each other.

Overall, this was a thorough and rewarding experiment which required data analysis, circuit design and the use of other techniques to be able to reduce noise and oscillations. Feel free to contact me if you would like to read the technical report on this.