Hello,
for my Electronic Circuits and Devices lab, I have to design a two stage amplifier using either bipolar or FET transistors or a combination of both, where I have to select suitable transistors capable of providing a voltage or a power gain of at least 100dB and covering frequencies from 100Hz to 10MHz.
In the course we only covered voltage gain so I first thought of looking through the voltage gain for the configurations we looked at in class and then divide the gain so that the product of the gain of both stages will give me the desired gain. However, looking through the different configurations such as the voltage divider common emitter or the fixed bias common emitter, the value of the voltage gain derived is always given with a minus sign for example for a voltage divider configuration Av = -Rc/re which means I'll have a negative gain! Please help me figure out what configuration to choose and why, and how will I get the gain I want.
The professor gave us a hint to use a buffer or common collector (emitter follower) stage in the design, but I don't exactly understand why.
Also, I have no idea how to deal with the bandwidth provided. Should I use the equations for the lower cut-off and higher cut-off frequencies. We studied that we calculate three lower cut-off and the dominant is the biggest value; and to calculate two higher cut-off frequencies for input and output where the dominant one is the lower. How will I use this here?
I'd appreciate if someone can "enlighten" me because I am seriously confused and the deadline is approaching.
Thank you (hope it was clear enough)
for my Electronic Circuits and Devices lab, I have to design a two stage amplifier using either bipolar or FET transistors or a combination of both, where I have to select suitable transistors capable of providing a voltage or a power gain of at least 100dB and covering frequencies from 100Hz to 10MHz.
In the course we only covered voltage gain so I first thought of looking through the voltage gain for the configurations we looked at in class and then divide the gain so that the product of the gain of both stages will give me the desired gain. However, looking through the different configurations such as the voltage divider common emitter or the fixed bias common emitter, the value of the voltage gain derived is always given with a minus sign for example for a voltage divider configuration Av = -Rc/re which means I'll have a negative gain! Please help me figure out what configuration to choose and why, and how will I get the gain I want.
The professor gave us a hint to use a buffer or common collector (emitter follower) stage in the design, but I don't exactly understand why.
Also, I have no idea how to deal with the bandwidth provided. Should I use the equations for the lower cut-off and higher cut-off frequencies. We studied that we calculate three lower cut-off and the dominant is the biggest value; and to calculate two higher cut-off frequencies for input and output where the dominant one is the lower. How will I use this here?
I'd appreciate if someone can "enlighten" me because I am seriously confused and the deadline is approaching.
Thank you (hope it was clear enough)